2010年10月MBA数学真题解析
2010年全国硕士研究生入学统一考试数学一试题解析
2010年全国硕士研究生入学统一考试数学一试题一、选择题(1~8小题,每小题4分,共32分.下列每题给出的四个选项中,只有一个选项符合题目要求的,请将所选项前的字母填在答题纸．．．指定位置上.) 1. （10年，4分） 极限2lim ()()xx x x a x b →∞⎡⎤=⎢⎥-+⎣⎦( ) (A ) 1. (B ) e . (C ) a be -. (D ) b ae-.【考查分析】“1∞”型极限的计算. 【详解】本题属于未定式求极限,极限为1∞型,故可以用“e 的抬起法”求解．()()2lim xx xx a x b →∞⎡⎤⎢⎥-+⎣⎦()()2lnlim x x x a x b x e ⋅-+→∞=()()2lim lnx x x x a x b e→∞⋅-+=,其中又因为()()2222()()lim ln lim ln 1()()()()lim()()()lim()()x x x x x x x a x b x x x a x b x a x b x x x a x b x a x b a b x abxx a x b a b→∞→∞→∞→∞--+⋅=+-+-+⎡⎤--+⎣⎦=-+-+=-+=-⎡⎤⎣⎦故原式极限为a be-,所以应该选择(C).2. （10年，4分） 设函数(,)z z x y =,由方程,0y z F x x ⎛⎫=⎪⎝⎭确定,其中F 为可微函数,且20F '≠,则z zxy x y∂∂+=∂∂( ) (A ) x . (B ) z . (C ) x -. (D ) z -. 【考查分析】隐函数偏导数的计算. 【详解】122212122221x z y z y zF F F F F yF zF z x x x x x F F xF F x⎛⎫⎛⎫''''-+-⋅+⋅ ⎪ ⎪'''+∂⎝⎭⎝⎭=-=-==∂''''⋅, 112211y z F F F z x y F F F x'⋅''∂=-=-=-∂'''⋅, 1212222yF zF yF F z z z x y z x y F F F ''''+⋅∂∂+=-==∂∂'''．选（B ）. 3. （10年，4分） 设,m n 是正整数,则反常积分()20ln 1mnx dx x-⎰的收敛性 ( )(A ) 仅与m 的取值有关. (B )仅与n 的取值有关.(C ) 与,m n 取值都有关. (D ) 与,m n 取值都无关. 【考查分析】判断反常积分的敛散性. 【详解】0x =与1x =都是瑕点.应分成()()()22211212ln 1ln 1ln 1mm mnnnx x x xxx---=+⎰⎰,用比较判别法的极限形式,对于()2120ln 1m nx x-,由于121012[ln (1)]lim 1mnx n mx xx+→--=.显然,当1201n m<-<,则该反常积分收敛. 当120n m -≤,1210[ln (1)]lim m x nx x+→-存在,此时()2120ln 1m n x x -实际上不是反常积分,故收敛. 故不论,m n 是什么正整数,dx 总收敛.对于,取01δ<<,不论,m n 是什么正整数,1211211[ln (1)]lim lim ln (1)(1)01(1)mnmx x x xx x x δδ--→→-=--=-,所以收敛,故选(D).【评注】(1)当210m m-≥时，⎰是定积分.(2) 0,0αβ∀>>,有lim ln 00x x x βα+=→. 4. （10年，4分） ()()2211limnnn i j nn i n j →∞===++∑∑ ( ) (A )()()120111xdx dy x y ++⎰⎰. (B ) ()()100111x dx dy x y ++⎰⎰. (C )()()11111dx dy x y ++⎰⎰. (D ) ()()1120111dx dy x y ++⎰⎰. 【考查分析】利用积分和式求极限. 【详解】()()222211111()nnnn i j i j n nn i n jn i n j =====++++∑∑∑∑22111()()n n j i n n j n i ===++∑∑ 12220211111lim lim ,11()nn n n j j n dy j n jn y n→∞→∞====+++∑∑⎰ 1011111lim lim ,11()nn n n i i n dx i n i n x n→∞→∞====+++∑∑⎰()()2222111111lim lim()()n nn nn n i j j i n n j n i n i n j →∞→∞=====++++∑∑∑∑ 221(lim )nn j n n j→∞==+∑1(lim )nn i nn i →∞=+∑ 1120011()()11dx dy x y =++⎰⎰()()11200111dx dy x y =++⎰⎰. 【评注】本题易认为是二重积分或误认为逐次极限.实际上,对i 求和时与j 无关,对j 求和时与i 无关,所以这是一道两个和得乘积的极限题.5. （10年，4分） 设A 为m n ⨯矩阵,B 为n m ⨯矩阵,E 为m 阶单位矩阵,若AB E =,则 ( )(A ) 秩()r A m =,秩()r B m =. (B ) 秩()r A m =,秩()r B n =. (C ) 秩()r A n =,秩()r B m =. (D ) 秩()r A n =,秩()r B n =. 【详解】由于AB E =,故()()r AB r E m ==.又由于()(),()()r AB r A r AB r B ≤≤,故(),()m r A m r B ≤≤ ①由于A 为m n ⨯矩阵,B 为n m ⨯矩阵,故(),()r A m r B m ≤≤ ②由①、②可得(),()r A m r B m ==,故选A .6. （10年，4分） 设A 为4阶实对称矩阵,且2A A O +=,若A 的秩为3,则A 相似于 ( )(A ) 1110⎛⎫ ⎪ ⎪ ⎪ ⎪⎝⎭. (B ) 1110⎛⎫ ⎪⎪ ⎪- ⎪⎝⎭. (C ) 1110⎛⎫ ⎪- ⎪ ⎪- ⎪⎝⎭. (D ) 1110-⎛⎫⎪- ⎪ ⎪- ⎪⎝⎭. 【考查分析】对称矩阵相似于对角矩阵.【详解】设λ为A 的特征值,由于2A A O +=,所以20λλ+=,即(1)0λλ+=,这样A 的特征值只能为-1或0.由于A 为实对称矩阵,故A 可相似对角化,即A Λ ,()()3r A r =Λ=,因此,1110-⎛⎫⎪- ⎪Λ= ⎪- ⎪⎝⎭,即1110A -⎛⎫⎪- ⎪Λ= ⎪- ⎪⎝⎭. 【评注】看清题目,说清每个已知条件的作用.即可得出结论.7. （10年，4分） 设随机变量X 的分布函数0,01(),0121,1x x F x x e x -<⎧⎪⎪=≤<⎨⎪-≥⎪⎩,则{}1P X == ( ) (A ) 0. (B )12. (C ) 112e --. (D ) 11e --. 【考查分析】本题主要考查分布函数的概念及随机事件概率的计算.已知分布函数,【详解】离散型随机变量的分布函数是跳跃的阶梯形分段函数,连续型随机变量的分布函数是连续函数.观察本题中()F x 的形式,得到随机变量X 既不是离散型随机变量,也不是连续型随机变量,所以求随机变量在一点处的概率,只能利用分布函数的定义.根据分布函数的定义,函数在某一点的概率可以写成两个区间内概率的差,即{}{}{}()()1111111110122P X P X P X F F e e --==≤-<=--=--=-,故本题选(C). 【评注】已知分布函数,求随机事件的概率是基本题,但需注意题中的随机变量既不是离散型也不是连续型.由于分布函数在1x =处不连续,故利用{1}(1)(10)P X F F ==--来计算.8. （10年，4分） 设1()f x 为标准正态分布的概率密度,2()f x 为[]1,3-上均匀分布的概率密度,若12(),0()(),0af x x f x bf x x ≤⎧=⎨>⎩,(0,0)a b >>为概率密度,则,a b 应满足 ( ) (A ) 234a b +=. (B ) 324a b +=. (C ) 1a b +=. (D ) 2a b +=. 【详解】根据题意知,()2212x f x e π-=(x -∞<<+∞),()21,1340,x f x ⎧ -≤≤⎪=⎨⎪ ⎩其它利用概率密度的性质:()1f x dx +∞-∞=⎰,故()()()()03121001312424a a f x dx af x dx bf x dx f x dxb dx b +∞+∞+∞-∞-∞-∞=+=+=+=⎰⎰⎰⎰⎰所以整理得到234a b +=,故本题应选(A).二、填空题(9 14小题,每小题4分,共24分.请将答案写在答题纸．．．指定位置上.) 9. （10年，4分） 设()20,ln 1,t tx e y u du -⎧=⎪⎨=+⎪⎩⎰ 求220t d y dx == . 【详解】因为 ()()22ln 1ln 1tttdy t e dx e -+==-+-,()()()()22222ln 12ln 11tt t td te d y dt t e t e e dx dt dx t -+⎡⎤=⋅=-⋅-+⋅-⎢⎥+⎣⎦,所以220t d y dx == 10. （10年，4分）2π=⎰.【考查分析】用变量变换与分部计算定积分.【详解】t =,2x t =,2dx tdt =,利用分部积分法,原式220cos 22cos 2sin t t tdt t tdt t d t πππ=⋅==⎰⎰⎰20002sin 2sin 4cos t t t tdt td t πππ⎡⎤=-=⎢⎥⎣⎦⎰⎰0004cos cos 4cos 4sin 4t t tdt t ππππππ⎡⎤=-=-=-⎢⎥⎣⎦⎰.11. （10年，4分） 已知曲线L 的方程为[]{}11,1y x x =- ∈-,起点是()1.0-,终点是()1,0,则曲线积分2Lxydx x dy +=⎰.【详解】12222LL L xydx x dy xydx x dy xydx x dy +=+++⎰⎰⎰()()()01221011x x dx x dx x x dx x dx -=+++-+-⎰⎰()()0122122x x dx x x dx -=++-⎰⎰1322310223223x x x x -⎛⎫⎛⎫=++- ⎪ ⎪⎝⎭⎝⎭211203223⎛⎫⎛⎫=--++-= ⎪ ⎪⎝⎭⎝⎭12. （10年，4分） 设(){}22,,1x y z xy z Ω=+≤≤,则Ω的形心的竖坐标z = .【详解】()2221221211000211212021r rrz d rdr zdxdydz d rdr zdzdxdydz d rdr dzd r rdrππθθθθΩΩ⎛⎫⎪⋅ ⎪⎝⎭==-⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰⎰4211222r d r drπθπ⎛⎫- ⎪⎝⎭=⎰⎰126204122r r d πθ⎛⎫- ⎪⎝⎭=⎰20112266322d πθπππ⋅===⎰. 13. （10年，4分） 设()()()1231,2,1,0,1,1,0,2,2,1,1,TTTa ααα=-==,若由123,,ααα生成的向量空间的维数是2,则a = . 【详解】因为由123,,ααα生成的向量空间维数为2,所以123(,,)2r ααα=. 对123(,,)ααα进行初等行变换：123112112112211013013(,,)1010130060202000a a a ααα⎛⎫⎛⎫⎛⎫⎪ ⎪ ⎪-- ⎪ ⎪ ⎪=→→ ⎪ ⎪ ⎪-- ⎪ ⎪ ⎪⎝⎭⎝⎭⎝⎭所以6a =.14. （10年，4分） 设随机变量X 的概率分布为{}!C P X k k ==,0,1,2,k = ,则()2E X = . 【考查分析】随机变量的数学期望,方差.泊松分布的期望,方差. 【详解】利用离散型随机变量概率分布的性质,知{}001!k k CP X k Ce k ∞∞======∑∑,整理得到1C e -=,即 {}111!!k e P X k e k k --===.故X 服从参数为1的泊松分布,则()()1,1E X D X ==,根据方差的计算公式有()()()222112E X D X E X =+=+=⎡⎤⎣⎦. 【评注】22()EX DX EX =+,所以应求X 的期望与方差,而X 的分布{},0,1,2,!CP X k k k === 的C 是待定常数.不难看出这是一个泊松分布. 三、解答题(15～23小题,共94分.请将解答写在答题纸．．．指定位置上.解答应写出文字说明、证明过程或演算步骤.) 15. （10年，10分）(本题满分10分)求微分方程322x y y y xe '''-+=的通解． 【考查分析】求常系数线性非齐次微分方程的通解. 【详解】对应齐次方程的特征方程为2320λλ-+=,解得特征根121,2λλ==,所以对应齐次方程的通解为212x x c y C e C e =+．设原方程的一个特解为*()x y x ax b e =+,则()()*22x y axax bx b e '=+++,()()*2422x y axax bx a b e ''=++++,代入原方程,解得1,2a b =-=-,故特解为*(2)xy x x e =--． 故方程的通解为*212(2)x x x c y y y C e C e x x e =+=+-+． 16. （10年，10分）(本题满分10分)求函数()()2221x t f x x t e dt -=-⎰的单调区间与极值.【考查分析】对变限求导数,划分单调区间,求极值. 【详解】 因为22222222111()()x x x t t t f x x t e dt x e dt te dt ---=-=-⎰⎰⎰,所以2224423311()2222x x t x x t f x x e dt x ex ex e dt ----'=+-=⎰⎰,令()0f x '=,则0,1x x ==±.又22421()24x t x f x e dt x e--''=+⎰,则21(0)20t f e dt -''=<⎰,所以2211111(0)(0)(1)22t t f t e dt e e ---=-=-=-⎰是极大值.而1(1)40f e -''±=>,所以(1)0f ±=为极小值.又因为当1x ≥时,()0f x '>；01x ≤<时,()0f x '<；10x -≤<时,()0f x '>；1x <-时,()0f x '<,所以()f x 的单调递减区间为(,1)(0,1)-∞- ,()f x 的单调递增区间为(1,0)(1,)-+∞ .【评注】(1)求()f x 的单调性区间就是求()f x '的正负号区间.增减或增减区间的分界点就是极值点.上述方法就是求出()f x ',然后分出()f x '的正负号区间,从而得到()f x 的增减区间,相应地得到()f x 的极值点.这里就不必去求驻点处得()f x ''.(2)若题目只要求()f x 的极值,我们也可以221()2x t f x x e dt -'=⎰后,解得驻点0x =,1x =±,然后再求驻点处的二阶导数.由于201(0)20t f e dt -''=<⎰,⇒11(0)(1)2f e -=-为极大值.由于1(1)40f e -''±=>,⇒(1)0f ±=为极小值.17. （10年，10分）(本题满分10分)(I)比较()1ln ln 1n t t dt +⎡⎤⎣⎦⎰与10ln nt t dt ⎰()1,2,n = 的大小,说明理由；(II)记()1ln ln 1nn u t t dt =+⎡⎤⎣⎦⎰()1,2,n = ,求极限lim n n u →∞. 【详解】(I)当01x <<时0ln(1)x x <+<,故[]ln(1)nnt t +<,所以[]ln ln(1)ln nn t t t t +<,则[]11ln ln(1)ln nn t t dt t t dt +<⎰⎰()1,2,n = .(II)()1111001ln ln ln 1nnn t t dt t t dt td t n +=-⋅=-+⎰⎰⎰ ()211n =+,故由 ()1210ln 1n n u t t dt n <<=+⎰,根据夹逼定理得()210lim lim01n n n u n →∞→∞≤≤=+,所以lim 0n n u →∞=.18. （10年，10分）(本题满分10分)求幂级数()121121n n n x n -∞=--∑的收敛域及和函数.【考查分析】求幂级数的收敛域及和函数. 【详解】(I) (1)1222(1)1122(1)(1)2(1)121lim lim (1)(1)2121n n n n n n n n n nx x n n xx n n +-++--→∞→∞--⋅+-+=--⋅--222(21)21lim lim 2121n n n x n x x n n →∞→∞--==⋅=++,所以,当21x <,即11x -<<时,原级数绝对收敛.当21x >时,原级数发散,因此幂级数的收敛半径1R =.当1x =±时,11211(1)(1)2121n n n n n x n n --∞∞==--⋅=--∑∑,由莱布尼兹判别法知,此级数收敛,故原级数的收敛域为[]1,1-. (II) 设1122111(1)(1)()2121n n nn n n S x x x x n n --∞∞-==⎛⎫--=⋅=⋅⋅ ⎪--⎝⎭∑∑,其中令12111(1)()21n n n S x x n -∞-=-=⋅-∑()1,1x ∈-,所以有 12221111()(1)()n n n n n S x xx ∞∞---=='=-⋅=-∑∑ ()1,1x ∈-,从而有 12211()1()1S x x x '==--+ ()1,1x ∈-,故 11201()(0)arctan 1xS x dx S x x =+=+⎰,()1,1x ∈-.1()S x 在1,1x =-上是连续的,所以()S x 在收敛域[]1,1-上是连续的.所以()arctan S x x x =⋅,[]1,1x ∈-.【评注】幂函数在收敛域上可以逐项积分,但逐项求导只能先在收敛区间进行.在逐项求导后，在另行讨论端点处是否成立。
2010年MBA联考数学真题及解答
)。
。
(A) -9 (B) -8 (C) -6 (D) 6 (E) 8
答案:C [解] 由{an}为等比数列可知a3a8=a4a7，且由韦达定理可知a3a8=-6，故a4a7=-6。 [评析] (1)知识点：本题考查等比数列的性质和韦达定理。 (2)注意事项：应注意数列的性质。 14. 某公司有9名工程师，张三是其中之一，从中任意抽调4人组成攻关小组，包括张三的概率是 ( )。 答案:D [解] ，算得 。 [评析] (1)知识点：本题考查古典概型。 (2)注意事项：理解题意、运算无误。 15. 在10道备选试题中，甲能答对8题，乙能答对6题，若某次考试从这10道备选题中随机抽出3 道题作为考题，至少答对2题才算合格，则甲乙两人考试都合格的概率是( )。
file:///C|/Documents and Settings/Administ...ocuments/My Snippets/MBA联考数学真题2010年10月.htm（第 5／8 页）[2012-12-7 12:12:11]
学校：班级：姓名：
答案:A [解] 由题意可知甲通过的概率为 ，乙通过的概率为 = ，且甲乙通过考试的事件是相互独立 的，则甲乙都通过的概率为 。 [评析] (1)知识点：本题考查事件相互独直。 (2)注：盘事项：本题摘自2004年福建省高考耻科试题，现将原题附上：甲、乙两人参加一次 英语口语考试，已知在备选的10道试题中，甲能答对其中的6题，乙能答对其中的8题。规定每次 考试每人分别都从这10道备选题中随机抽出3题进行测试，至少答对2题才算合格。求甲、乙两人 至少有一人：考试合格的概率，作为复习练习，考生可以解一下，答案为 。 二、条件充分性判断 (A) ：条件(1)充分，但条件(2)不充分 (B) ：条件(2)充分，但条件(1)不充分 (C) ：条件(1)和条件(2)单独都不充分，但条件(1)和条件(2)联合起来充分 (D) ：条件(1)充分，条件(2)也充分 (E) ：条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分 16. 12支篮球队进行单循环比赛，完成全部比赛共需11天。 (1)每天每队只比赛1场 (2)每天每队比赛2场 答案:A [解] 由于是单循环，故总比赛场次为 =66，由条件(1)可知每队每天比赛一场，即一天比赛6 场，故需比赛11天。 [评析] (1)知识点：本题考查排列、组合。 (2)注意事项：此题如将单循环改成淘汰赛，直至产生冠军，其他题干不变，将条件(1)改成每 天比赛一场，则仍选(A) 。 17. (1) (2) 答案:B [解] 此题由两个递推式子是不可能推出一个通项的，故非A 即 B，观察可知题干为 即1-xn为等 比数列，由条件(1)1-xn=2xn+1,可知条件(1)不成立。 [评析] (1)知识点：本题考查等比数列。 (2)注意事项：本题正解为由条件(2)可知2xn+1=1+xn可以得到-2xn+1=1-xn两边刚加2，得2(1xn+1)=(1-xn)， 即1-xn为首项为 ，公比为 的等比数列，可得 。 18. 直线y=ax+b经过第一、二、四象限。 (1)a＜0 (2)b＞0 答案:C [解] 题目有两个未知数，而条件(1)和条件(2)各说1个。 评注：对于y=kx+b而言：过二，四象限，则k＜0，而过一象限，则截距大于0，即b＞0 [评析] (1)知识点：本题考查直线斜截式过各象限的k，b特点。 (2)注意事项：对函数特点的把握。
2010 AMC 10A 试题及答案解析
2010 AMC 10A problems and solutions.The test was held on February 8, 2010. The first link contains the full set of test problems. The rest contain each individual problem and its solution.Problem 1Mary’s top book shelf holds five books with the follow ing widths, incentimeters: , , , , and . What is the average book width, in centimeters?SolutionTo find the average, we add up the widths , , , , and , to get a total sum of . Since there are books, the average book width isThe answer is .Problem 2Four identical squares and one rectangle are placed together to form one large square as shown. The length of the rectangle is how many times as large as its width?SolutionLet the length of the small square be , intuitively, the length of the big square is . It can be seen that the width of the rectangle is .Thus, the length of the rectangle is times large as the width. The answer is .Problem 3Tyrone had marbles and Eric had marbles. Tyrone then gave some of his marbles to Eric so that Tyrone ended with twice as many marbles as Eric. How many marbles did Tyrone give to Eric?SolutionLet be the number of marbles Tyrone gave to Eric. Then,. Solving for yields and . The answer is .Problem 4A book that is to be recorded onto compact discs takes minutes to read aloud. Each disc can hold up to minutes of reading. Assume that the smallest possible number of discs is used and that each disc contains the same length of reading. How many minutes of reading will each disc contain?SolutionAssuming that there were fractions of compact discs, it would take CDs to have equal reading time. However, since the number of discs can only be a whole number, there are at least 8 CDs, in which case it would have minutes on each of the 8 discs. The answer is .Problem 5The area of a circle whose circumference is is . What is the value of ?SolutionIf the circumference of a circle is , the radius would be . Since the area of a circle is , the area is . The answer is . Problem 6For positive numbers and the operation is defined asWhat is ?Solution. Then, is The answer isProblem 7Crystal has a running course marked out for her daily run. She starts this run by heading due north for one mile. She then runs northeast for one mile, then southeast for one mile. The last portion of her run takes her on a straight line back to where she started. How far, in miles is this last portion of her run?SolutionCrystal first runs North for one mile. Changing directions, she runs Northeast for another mile. The angle difference between North and Northeast is 45 degrees. She then switches directions to Southeast, meaning a 90 degree angle change. The distance now from travelling North for one mile, and her current destination is miles, because it is the hypotenuse of a 45-45-90 triangle with side length one (mile). Therefore, Crystal's distance from her starting position, x, is equal to , which is equal to . The answer isTony works hours a day and is paid $per hour for each full year of his age. During a six month period Tony worked days and earned $. How old was Tony at the end of the six month period?SolutionTony worked hours a day and is paid dollars per hour for each full year of his age. This basically says that he gets a dollar for each year of his age. So if he is years old, he gets dollars a day. We also know that he worked days and earned dollars. If he was years old at the beginning of his working period, he would have earned dollars. If he was years old at the beginning of his working period, he would have earned dollars. Because he earned dollars, we know that he was for some period of time, but not the whole time, because then the money earned would be greater than or equal to . This is why he was when he began, but turned sometime in the middle and earned dollars in total. So the answer is .The answer is . We could find out for how long he was and . . Then isand we know that he was for days, and for days. Thus, the answer is .Problem 9A palindrome, such as , is a number that remains the same when its digits are reversed. The numbers and are three-digit and four-digit palindromes, respectively. What is the sum of the digits of ?Solutionis at most , so is at most . The minimum value ofis . However, the only palindrome between and is , which means that must be .It follows that is , so the sum of the digits is .Marvin had a birthday on Tuesday, May 27 in the leap year . In what year will his birthday next fall on a Saturday?Solution(E) 2017There are 365 days in a non-leap year. There are 7 days in a week. Since 365 = 52 * 7 + 1 (or 365 is congruent to 1 mod 7), the same date (after February) moves "forward" one day in the subsequent year, if that year is not a leap year.For example: 5/27/08 Tue 5/27/09 WedHowever, a leap year has 366 days, and 366 = 52 * 7 + 2. So the same date (after February) moves "forward" two days in the subsequent year, if that year is a leap year.For example: 5/27/11 Fri 5/27/12 SunYou can keep count forward to find that the first time this date falls on a Saturday is in 2017:5/27/13 Mon 5/27/14 Tue 5/27/15 Wed 5/27/16 Fri 5/27/17 Sat Problem 11The length of the interval of solutions of the inequality is . What is ?SolutionSince we are given the range of the solutions, we must re-write the inequalities so that we have in terms of and .Subtract from all of the quantities:Divide all of the quantities by .Since we have the range of the solutions, we can make them equal to .Multiply both sides by 2.Re-write without using parentheses.Simplify.We need to find for the problem, so the answer isProblem 12Logan is constructing a scaled model of his town. The city's water tower stands 40 meters high, and the top portion is a sphere that holds 100,000 liters of water. Logan's miniature water tower holds 0.1 liters. How tall, in meters, should Logan make his tower?SolutionThe water tower holds times more water than Logan's miniature. Therefore, Logan should make his towertimes shorter than the actual tower. This ismeters high, or choice .Problem 13Angelina drove at an average rate of kph and then stopped minutes for gas. After the stop, she drove at an average rate of kph. Altogether she drove km in a total trip time of hours including the stop. Which equation could be used to solve for the time in hours that she drove before her stop?SolutionThe answer is （）because she drove at kmh for hours (the amount of time before the stop), and 100 kmh for because she wasn't driving for minutes, or hours. Multiplying by gives the total distance, which is kms. Therefore, the answer isProblem 14Triangle has . Let and be on and , respectively, such that . Let be the intersection of segments and , and suppose that is equilateral. What is ?SolutionLet .Since ,Problem 15In a magical swamp there are two species of talking amphibians: toads, whose statements are always true, and frogs, whose statements are always false. Four amphibians, Brian, Chris, LeRoy, and Mike live together in this swamp, and they make the following statements.Brian: "Mike and I are different species."Chris: "LeRoy is a frog."LeRoy: "Chris is a frog."Mike: "Of the four of us, at least two are toads."How many of these amphibians are frogs?SolutionSolution 1We can begin by first looking at Chris and LeRoy.Suppose Chris and LeRoy are the same species. If Chris is a toad, then what he says is true, so LeRoy is a frog. However, if LeRoy is a frog, then he is lying, but clearly Chris is not a frog, and we have a contradiction. The same applies if Chris is a frog.Clearly, Chris and LeRoy are different species, and so we have at least frog out of the two of them.Now suppose Mike is a toad. Then what he says is true because we already have toads. However, if Brian is a frog, then he is lying, yet his statement is true, a contradiction. If Brian is a toad, then what he says is true, but once again it conflicts with his statement, resulting in contradiction.Therefore, Mike must be a frog. His statement must be false, which means that there is at most toad. Since either Chris or LeRoy is already a toad, Brain must be a frog. We can also verify that his statement is indeed false.Both Mike and Brian are frogs, and one of either Chris or LeRoy is a frog, so we have frogs total.Solution 2Start with Brian. If he is a toad, he tells the truth, hence Mike is a frog. If Brian is a frog, he lies, hence Mike is a frog, too. Thus Mike must be a frog.As Mike is a frog, his statement is false, hence there is at most one toad.As there is at most one toad, at least one of Chris and LeRoy is a frog. But then the other one tells the truth, and therefore is a toad. Hence we must have one toad and three frogs.Problem 16Nondegenerate has integer side lengths, is an angle bisector, , and . What is the smallest possible value of the perimeter?SolutionBy the Angle Bisector Theorem, we know that . If we use the lowest possible integer values for AB and BC (the measures of AD and DC, respectively), then , contradicting the Triangle Inequality. If we use the next lowest values (and ), the Triangle Inequality is satisfied. Therefore, our answer is , or choice .Problem 17A solid cube has side length inches. A -inch by -inch square hole is cut into the center of each face. The edges of each cut are parallel to the edges of the cube, and each hole goes all the way through the cube. What is the volume, in cubic inches, of the remaining solid?SolutionSolution 1Imagine making the cuts one at a time. The first cut removes a box . The second cut removes two boxes, each of dimensions, and the third cut does the same as the second cut, on the last two faces. Hence the total volume of all cuts is .Therefore the volume of the rest of the cube is.Solution 2We can use Principle of Inclusion-Exclusion to find the final volume of the cube.There are 3 "cuts" through the cube that go from one end to the other. Each of these "cuts" has cubic inches. However, we can not just sum their volumes, as the central cube is included in each of these three cuts. To get the correct result, we can take the sum of the volumes of the three cuts, and subtract the volume of the central cube twice.Hence the total volume of the cuts is.Therefore the volume of the rest of the cube is.Solution 3We can visualize the final figure and see a cubic frame. We can find the volume of the figure by adding up the volumes of the edges and corners.Each edge can be seen as a box, and each corner can be seen as a box..Problem 18Bernardo randomly picks 3 distinct numbers from the setand arranges them in descending order to form a 3-digit number. Silvia randomly picks 3 distinct numbers from the set and also arranges them in descending order to form a 3-digit number. What is the probability that Bernardo's number is larger than Silvia's number?SolutionWe can solve this by breaking the problem down into cases and adding up the probabilities.Case : Bernardo picks . If Bernardo picks a then it is guaranteed that his number will be larger than Silvia's. The probability that he will pick a is .Case : Bernardo does not pick . Since the chance of Bernardo picking is , the probability of not picking is .If Bernardo does not pick 9, then he can pick any number from to . Since Bernardo is picking from the same set of numbers as Silvia, the probability that Bernardo's number is larger is equal to the probability that Silvia's number is larger.Ignoring the for now, the probability that they will pick the same number is the number of ways to pick Bernardo's 3 numbers divided by the number of ways to pick any 3 numbers.We get this probability to beProbability of Bernardo's number being greater isFactoring the fact that Bernardo could've picked a but didn't:Adding up the two cases we getProblem 19Equiangular hexagon has side lengthsand . The area of is of the area of the hexagon. What is the sum of all possible values of ?SolutionSolution 1It is clear that is an equilateral triangle. From the Law of Cosines, we get that . Therefore, the area of is .If we extend , and so that and meet at , and meet at , and and meet at , we find that hexagon is formed by taking equilateral triangle of side length and removing three equilateral triangles, , and , of side length . The area of is therefore.Based on the initial conditions,Simplifying this gives us . By Vieta's Formulas we know that the sum of the possible value of is .Solution 2As above, we find that the area of is .We also find by the sine triangle area formula that, and thusThis simplifies to.Problem 20A fly trapped inside a cubical box with side length meter decides to relieve its boredom by visiting each corner of the box. It will begin and end in the same corner and visit each of the other corners exactly once. To get from a corner to any other corner, it will either fly or crawl in a straight line. What is the maximum possible length, in meters, of its path?SolutionThe distance of an interior diagonal in this cube is and the distance of a diagonal on one of the square faces is . It would not make sense if the fly traveled an interior diagonal twice in a row, as it would return to the point it just came from, so at most the final sum can only have 4 as the coefficient of . The other 4 paths taken can be across a diagonal on one of the faces, so the maximum distance traveled is.Problem 21The polynomial has three positive integer zeros. What is the smallest possible value of ?SolutionBy Vieta's Formulas, we know that is the sum of the three roots of the polynomial . Also, 2010 factors into. But, since there are only three roots to the polynomial, two of the four prime factors must be multiplied so that we are left with three roots. To minimize , and should be multiplied, which means will be and the answer is .Problem 22Eight points are chosen on a circle, and chords are drawn connecting every pair of points. No three chords intersect in a single point insidethe circle. How many triangles with all three vertices in the interior of the circle are created?SolutionTo choose a chord, we know that two points must be chosen. This implies that for three chords to create a triangle and not intersect at a single point, six points need to be chosen. Therefore, the answer is which is equivalent to 28,Problem 23Each of 2010 boxes in a line contains a single red marble, and for , the box in the position also contains white marbles. Isabella begins at the first box and successively draws a single marble at random from each box, in order. She stops when she first draws a red marble. Let be the probability that Isabella stops afterdrawing exactly marbles. What is the smallest value of for which ?SolutionThe probability of drawing a white marble from box is . Theprobability of drawing a red marble from box is .The probability of drawing a red marble at box is thereforeIt is then easy to see that the lowest integer value of that satisfies the inequality is .Problem 24The number obtained from the last two nonzero digits of is equal to . What is ?SolutionWe will use the fact that for any integer ,First, we find that the number of factors of in is equal to. Let . The we want is therefore the last two digits of , or . Since there is clearly an excess of factors of 2, we know that , so it remains to find .If we divide by by taking out all the factors of in , we canwrite as where where every multiple of 5 is replaced by the number with all its factors of 5 removed. Specifically, every number in the form is replaced by , and every number in the form is replaced by .The number can be grouped as follows:Using the identity at the beginning of the solution, we can reducetoUsing the fact that (or simply the fact that if you have your powers of 2 memorized), we can deduce that . Therefore.Finally, combining with the fact that yields.Problem 25Jim starts with a positive integer and creates a sequence of numbers. Each successive number is obtained by subtracting the largest possible integer square less than or equal to the current number until zero is reached. For example, if Jim starts with , then his sequence contains numbers:Let be the smallest number for which Jim’s sequence has numbers. What is the units digit of ?SolutionWe can find the answer by working backwards. We begin with on the bottom row, then the goes to the right of the equal's sign in the row above. We find the smallest value for whichand , which is .We repeat the same procedure except with for the next row and for the row after that. However, at the fourth row, wesee that solving yields , in which case it would be incorrect since is not the greatest perfect square less than or equal to . So we make it a and solve . We continue on using this same method where we increase the perfect square until can be made bigger than it. When we repeat this until we have rows, we get:Hence the solution is the last digit of , which is .。
2010MBA真题及详解
一、问题求解（第1~15小题，每小题3分，共45分）下列每题给出的A 、B 、C 、D 、E 五个选项中，只有一项是符合试题要求的，请在答题卡上将所选项的字母涂黑。
1.电影开演时观众中女士与男士人数之比为5：4，开演后无观众入场，放映一小时后，女士的20%，男士的15%离场，则此时在场的女士与男士人数之比为（ ）A.4：5B.1：1C.5：4D.20：17E.85：642.某商品的成本为240元，若按商品标价的8折出售，利润率为15%，则该商品的标价为（ ）A.276元B.331元C.345D.360元E.400元3.三名小孩中有一名学龄前儿童（年龄不足6岁），他们的年龄都是质数（素数），且依次相差6岁，他们的年龄之和为（ ）A.21岁B.27岁C.33岁D.39岁E.51岁4.在右边的表格中，每行为等差数列，每列为等比数列，则x+y+z =（ ）A.2B.52C.3 D 72E.4 5.如图I ，直角三角形ABC 区域内部有座山，现计划从BC 边上的某点D 开凿一条隧道到点A ，要求隧道长度最短，已知AB 长为5km ，AC 长为12km ，则所开凿的隧道AD 的长度约为（ ）A.4.12kmB.4.22kmC.4.42kmD.4.62kmE.4.92km6.某商店举行店庆活动，顾客消费达到一定数量后，可以在4件赠品中随机选取2件不同的赠品，任意两位顾客所选的赠品中，恰有1件品种相同的概率是（ ） A.16 B.14 C.13 D.12 E.237.多项式326x ax bx ++-的两个因式是12x x --和，则其第三个一次因式为（ ）A.6x -B.3x -C.1x +D.2x +E.3x +8.某公司的员工中，拥有本科毕业证、计算机登记证、骑车驾驶证的人数分别为130，110，90. 又知只有一种证的人数为140人，三证齐全的人数为30人，则恰有双证的人数为（ ）A.45B.50C.52D.62E.1009.甲商店销售某种商品，该商品的进价为每件90元，若每件定价为100元，则一天能售出500件，在此基础上，定价每增加1元，一天便少售出10件，甲商店欲获得最大利润，则该商品的定价应为（ ）A115元 B.120元 C.125元 D.130元 E.135元10.已知直线30(0,0)ax by a b -+=>>过圆224210xx y y ++-+=的圆心，则a b ⋅的最大值为（ ） A.916 B.1116 C.34 D.98 E.9411.某大学派出5名志愿者到西部4所中学支教，若每所中学至少一名志愿者，则不同的分配方案共有（ ）A.240种B.144种C.120种D.60种E.24种12.某装置的启动密码是由0到9中的三位不同数字组成，连续输入3次错误密码，就会导致该装置永久关闭，一个仅记得密码是由3个不同数字组成的人能够启动此装置的概率为（ ） A.1120 B.1168 C.1240 D.1720 E.31000213.某居民小区决定投资15万元修建停车位，据测算，修建一个室内车位的费用为5000元，修建一个室外车位的费用为1000元，考虑到实际因素，计划室外车位的数量不少于室内车位的2倍，也不多于室内车位的3倍，这笔投资最大可建车位的数量为（ ）A.78B.74C.72D.70E.6614.如图II ，长方形ABCD 的两条边长分别为8m 和6m ，四边形OEFG 的面积是4m 2，则阴影部分的面积为（ ）A.32m 2B.28m 2C.24m 2D.20m 2E.16m 215.在一次竞猜活动中，设有5关，如果连续通过2关就算闯关成功，小王通过每关的概率都是12，他闯关成功的概率为（ ） A.18 B.14 C.38 D.48 E.1932 二、条件充分性判断（本大题共10小题，每小题3分，共30分）解题说明：本大题要求判断所给出的条件能否充分支持题干中陈述的结论。
2010年MBA数学真题 答案详解
⎧5x + 4 y ⎨⎩4x + 5 y
= 50 ⇒
= 47
⎧ ⎪⎪
x
=
⎨
⎪ ⎪⎩
y
=
62
9， 35
9
所以甲商品利润比乙商品利润高，充分，
故正确答案为 C 19.【答案】D
【解析】
条件（1）中，
⎧d = ⎨⎩a1 +
−2 a2 +
a3
+
a4
=
12
⇒
a4
=
0
，条件（1）充分，
条件（2）中，
⎨⎧⎩aa12
故条件（1）充分； 条件（2）同样假设通过的男生有 x 人，未通过的男生有 x+6 人，则有 2x+6=24，即 x=9.
故条件（2）充分 故正确答案为 D. 23.【答案】A
【解析】 条件（1）中产值为首项为 a，公比为（1+p）的等比数列，由等比数列和公式可知：
Sn
=
a[1− (1+ 1− (1+
心，所以 −2a − b + 3 = 0 ，即 b = 3 − 2a ，故 a × b = a(3 − 2a) = −2a2 + 3a ，当 a = 3 时， 4
有最大值为 9 ，故正确答案为 D 8
11.【答案】A 【解析】
由题意知要想让每一学校至少有一名志愿者，那么表明有一所学校是两名志愿者，
那么总的方案有 C52 A44 = 10 × 4 × 3× 2 = 240 种，故选 A
p)12 ] p)
=
a [(1+ p
p)12
−1] ，所以条件（1）充分.
条件（2）中利用同一公式可计算结果如下：
MBA联考综合能力数学(古典概率、随机事件的独立性)历年真题试卷
MBA联考综合能力数学（古典概率、随机事件的独立性）历年真题试卷汇编1(题后含答案及解析)题型有：1. 问题求解 2. 条件充分性判断问题求解本大题共15小题，每小题3分，共45分。
下列每题给出的五个选项中，只有一项是符合试题要求的。
1．[2015年12月]在分别标记了数字1、2、3、4、5、6的6张卡片中随机取3张．其上数字之和等于10的概率为( )。
A．0．05B．0．1C．0．15D．0．2E．0．25正确答案：C解析：从6张卡片中随机取3张，共有C63=20种取法，10可以分成1，3，6或1，4，5或2，3，5的和，则数字之和等于10的概率为=0．15。
故选C。
知识模块：古典概率2．[2015年12月]从1到100的整数中任取一个数，则该数能被5或7整除的概率为( )。
A．0．02B．0．14C．0．2D．0．32E．0．34正确答案：D解析：1到100的整数中能被5整除的有20个，能被7整除的有14个，能同时被5和7整除的有两个(即35和70)，则所求概率为=0．32。
故选D。
知识模块：古典概率3．[2014年12月]某次网球比赛四强，甲对乙、丙对丁，两场比赛的胜者争夺冠军，各队之间相互获胜的概率为则甲获得冠军的概率为( )。
A．0．165B．0．245C．0．275D．0．315E．0．330正确答案：A解析：甲获胜的情况可分为两类。
第一类：甲胜乙，丙胜丁，甲胜丙，其概率为0．3×0．5×0．3=0．045。
第二类：甲胜乙，丁胜丙，甲胜丁，其概率为0．3×0．5×0．8=0．12，则甲获胜的概率为0．045+0．12=0．165。
知识模块：古典概率4．[2014年1月]某项活动中，将3男3女6名志愿者随机地分成甲、乙、丙三组，每组2人，则每组志愿者都是异性的概率为( )。
A．B．C．D．E．正确答案：E解析：6名志愿者随机分到甲、乙、丙三组，每组2人，则共有C62C42C22=90种分法，每组志愿者都是异性的分法有A33A33=36种，所求的概率为。
(完整版)MBA历年试题解析
2009年10月在职攻读工商管理硕士学位全国联考综合能力数学试题一.问题求解（第15~1小题，每小题3分，共45分，下例每题给 出A 、B 、C 、D 、E 五个选项中，只有一项是符合试题要求的，请在答题卡上将所选项的字母涂黑）1. 已知某车间的男工人数比女工人数多80%,若在该车间的一次技术考核中全体工人的平均成绩为75分,而女工平均成绩比男工平均成绩高20%,则女工平均成绩为（）分。
（A ）88 （B ）86 （C ）84 （D ）82 （E ）80[点拨]未知量设少的一方容易计算。
解：设女工人数为x ，男工平均成绩为y ，则842.170758.18.12.1=⇒=⇒=+⨯+⨯y y xx x y x y ，选（C ）。
2.某人在市场上买猪肉，小贩称得肉重为4斤，但此人不放心，拿出一个自备的100克重的砝码，将肉与砝码一起让小贩用原秤复称，结果重量为25.4斤，由此可知顾客应要求小贩补猪肉（）两（A ）3 （B ）6 （C ）4 （D ）7 （E ）8[点拨]比例问题，但应先化为同一计量单位。
解：32405.22=⇒=x x ，应要求小贩补猪肉83240=-两。
选（E ）。
3. 甲、乙两商店某种商品的进价都是200元，甲店以高于进价20%的价格出售，乙店以高于进价15%的价格出售，结果乙店的售出件数是甲店的两倍，扣除营业税后乙店的利润比甲店多5400元。
若营业税率是营业额的5%，那么甲、乙两店售出该商品各为（）件（A ）450，900 （B ）500，1000 （C ）550，1100（D ）600，1200 （E ）650，1300[点拨]直接设甲店售出件数，在利用利润差。
解：设甲店售出x 件，则甲店的利润为 x x x 28%52.12002.0200=⨯⨯-⨯， 乙店的利润为 x x x 37%5215.1200215.0200=⨯⨯⨯-⨯⨯，60054002837=⇒=-x x x 。
2010年10月管理类联考逻辑真题(吕建刚老师解析版)MBA、MPACC、MPA
吕建刚老师解析2010年10月MBA/MPACC/MPA管理类联考逻辑真题2010-10-26.许多企业深受目光短浅之害，他们太关注立竿见影的结果和短期目标，以至于无法高瞻远瞩，往往使企业陷于被动甚至导致破产。
因此，企业领导层的决策和行动应该以长期目标为主，不需过分关注短期目标。
以下哪项如果为真，将最有力地削弱上述论证？A.短期目标对员工的激励效果比长期目标更好。
B.长期目标有较大的不确定性，短期目标易于控制。
C.长期目标的现实有赖于一个个短期目标的成功。
D.企业的短期目标和长期目标对于企业的发展都重要。
E.企业的发展收到企业外部环境等诸多因素的影响。
【解析】削弱题题干：企业领导层的决策和行动应该以长期目标为主，不需过分关注短期目标。
选项C 指出，长期目标依赖于短期目标的实现，短期目标是实现长期目标的必要条件，所以必须要关注短期目标。
【答案】C2010-10-27.总经理：建议小李和小孙都提拔。
董事长：我有不同意见。
以下哪项符合董事长的意思？A.小李和小孙都不提拔。
B.提拔小李，不提拔小孙。
C.不提拔小李，提拔小孙。
D.除非不提拔小李，否则不提拔小孙。
E.要么不提拔小李，要么不提拔小孙。
【解析】形式逻辑题总经理：提拔小李∧提拔小孙；董事长：并非（提拔小李∧提拔小孙），等价于：﹁提拔小李∨﹁提拔小孙，等价于：提拔小李→﹁提拔小孙，等价于：提拔小孙→﹁提拔小李。
D 选项：﹁不提拔小李→﹁提拔小孙，即：提拔小李→﹁提拔小孙，与董事长的意思相符。
【答案】D2010-10-28.大气和云层既可以折射也可以吸收部分太阳光，约有一半照射地球的太阳能被地球表面的土地和水面吸收，这一热能值十分巨大。
由此可以得出：地球将会逐渐升温以致融化。
然而，幸亏有一个可以抵消此作用的因素，即：以下哪项作为上述的后续最为恰当？A.地球发散到外空的热能值与其吸收的热能值相近。
B.通过季风与洋流，地球赤道的热向两极方向扩散。
吕建刚老师讲逻辑C.在日食期间，由于月球的阻挡，照射到地球的太阳光线明显减少。
MBA联考综合能力数学平均值函数历年真题试卷汇编1_真题(含答案与解析)-交互
MBA联考综合能力数学（平均值、函数）历年真题试卷汇编1(总分58, 做题时间90分钟)1. 问题求解问题求解本大题共15小题。
下列每题给出的五个选项中，只有一项是符合试题要求的。
1.[2013年1月]甲班共有30名学生，在一次满分为100分的考试中，全班平均成绩为90分，则成绩低于60分的学生至多有( )。
SSS_SINGLE_SELA 8个B 7个C 6个D 5个E 4个该问题分值: 2答案:B解析：设60分以下的学生有x人，则他们的总分至多为59x，剩下人的分数和至多为100(30—x)，因此总分至多为59x+100(30—x)=3 000—41x，由题意知3 000—41x≥30×90，解得x≤7，即至多7人，因此选B。
2.[2010年10月]某学生在军训时进行打靶测试，共射击10次。
他的第6、7、8、9次射击分别射中9．0环、8．4环、8．1环、9．3环，他的前9次射击的平均环数高于前5次的平均环数。
若要使10次射击的平均环数超过8．8环，则他第10次射击至少应该射中( )(打靶成绩精确到0．1环)。
SSS_SINGLE_SELA 9．0环B 9．2环C 9．4环D 9．5环E 9．9环该问题分值: 2答案:E解析：第6、7、8、9次射击的平均环数为=8．7，而10次射击的平均环数超过8．8环，则总环数至少为8．8×10+0．1，则前9次射击的总环数至多为8．7×9—0．1．则第10次射击至少为(8．8×10+0．1)一(8．7×9—0．1)=9．9环。
因此选E。
3.[2009年10月]已知某车间的男工人数比女工人数多80％，若在该车间一次技术考核中全体工人的平均成绩为75分．而女工平均成绩比男工平均成绩高20％，则女工的平均成绩为( )。
SSS_SINGLE_SELA 88分B 86分C 84分D 82分E 80分该问题分值: 2答案:C解析：设女工人数为x，男工平均成绩为y，利用十字交叉法，有即，解得y=70，所以女工平均成绩为70×1．2=84。
2010年10月在职MBA联考真题及答案解析
2010年10月在职MBA联考真题及答案解析26. 许多企业深受目光短浅之害，他们太关注立竿见影的结果和短期目标，以至于无法高瞻远瞩，往往使企业陷于被动甚至导致破产。
因此，企业领导层的决策和行动应该以长期目标为主，不需过分关注短期目标以下哪项如果为真，将最有力地削弱上述论证？A. 短期目标对员工的激励效果比长期目标更好。
B. 长期目标有较大的不确定性，短期目标易于控制。
C. 长期目标的现实有赖于一个个短期目标的成功。
D. 企业的短期目标和长期目标对于企业的发展都重要。
E. 企业的发展收到企业外部环境等诸多因素的影响。
27. 总经理：建议小李和小孙都提拔。
董事长：我有不同意见。
以下哪项符合董事长的意思？A. 小李和小孙都不提拔。
B. 提拔小李，不提拔小孙。
C. 不提拔小李，提拔小孙。
D. 除非不提拔小李，否则不提拔小孙。
E. 要么不提拔小李，要么不提拔小孙。
28. 大气和云层既可以折射也可以吸收部分太阳光，约有一半照射地球的太阳能被地球表面的土地和水面吸收，这一热能值十分巨大。
由此可以得出：地球将会逐渐升温以致融化。
然而，幸亏有一个可以抵消此作用的因素，即：以下哪项作为上述的后续最为恰当？A. 地球发散到外空的热能值与其吸收的热能值相近。
B. 通过季风与洋流，地球赤道的热向两极方向扩散。
C. 在日食期间，由于月球的阻挡，照射到地球的太阳光线明显减少。
D. 地球核心因为热能积聚而一直呈熔岩状态。
E. 由于二氧化碳排放增加，地球的温室效应引人关注。
29. 如果面粉价格继续上涨，佳食面包店的面包成本必将大幅度增加。
在这种情况下，佳食面包店将会考虑以扩大饮料的经验来弥补面包销售利润的下降。
但是，佳食面包店只有保证面包销售利润不下降，才可避免整体收益明显减少。
以下哪项陈述可以从上文逻辑地得出？A. 如果佳食面包店的整体收益减少，它购买面粉的成本将继续增加。
B. 如果佳食面包店的整体收益减少，要么扩大饮料的经营，要么减少面包的销售。