向中国女排学习，(2) MATH JJ[转帖]

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向中国女排学习，(2) MATH JJ 转自CD，作者：cmtn Math 1. 4个same big sandwiches, divided to m students (M>4), first 3 divided to m, last one divided by (m-4), cause 4 of the students want none of sandwiches. C ate a piece of all 4, ask portion of C ate. 文字较长有点读不懂，花了５分钟 几点澄清： 文字比较搞，大约６－７行，看了三遍没看懂（水平太低），最后理解为，四种sandwiches，Ｍ个students，前三个分成Ｍ份，第四个分成（Ｍ－４）份，Ｃ吃了４份，每种一份。问吃了占总数的多少。题目不难。现在想想应该(M-3)/(M(M-4)), 既 (3/m+1/(M-4))/4 A） (m-4)/(m(m-4)) B） (4m-4)/(m(m-4)) C） (m-3)/(m(m-4)) D） (m-8)/(m(m-4)) E） (4m-12)/(m(m-4)) Ans: C 2. m0? I. ml>0 II. pt>0 III. tz>0 A) I II B) II III C) I II III D) ??? E) can’t Ans: E 3. L1, L2, ……….L10, 对应M1 to M10, L integer, where M is remainder of L divided by 2, ASK sum of M 1) sun of L = 100 2) six of L is even ANS: B 4. 2 lines L ang K, slope L > K? 1) L pass (4,0) K pass (3,0) 2) L pass (0,-3) K pass (0,-4) ANS: C 5. K=wxyz, where w, x, y, z prime, ask No. OF factor exclude 1 and K A) 6 B) 8 C) 10 D) 12 E) 14 ANS: E 6. M=xyz where w, x, y, z prime, ask No. OF factor. ( my last one, like to be test) A) 2 B) 3 C) 4 D) 6 E) 8 ANS: E 7. X1, X2 …X5, X 是3的等比数列，X5-X2=39 ASK X1? A) 1/3 B) 1/2 C) 1 D) 2 E) 7 ANS: B 8. ASK median may be which of the following, >40 16.5%, >35中>40占33.33% I) 34 II) 35 III) 36 A) I B) I and II C) II and III D) I, II and III E) None ANS: B 9. Club B member >10, Club A中是club B的占30%, ASK which has more members. 1) club B has 600 members 2) Club B中是club A的占40% ANS: B 10. old JJ, use 26 character to make 3 characters password, only mid should be one of AEIOU, the other two not same. ASK no. Of passwords ANS: 2100 11. rectangle ABDE, C is a point on BD, F and G are two points on AE (has figure). Area of ABDE=24. Ask triangle CFG area 1) AB=4 2) FG=AE/3 ANS: B 12. 8[(2X+3Y)-Y]+2X+3Y=18X+KY (Y<>0), ask K A) 16 B) 17 C) 18 D) 19 E) 20 ANS: D 13. A invest X on the rate of 10%, B invest Y on the rate of 6%, ask X/Y I) at end of first month A and B have the same amount of money in their accounts. II) A get xxx interest, B get yyy interest. (xxx, and yyy are real number, can’t remember) ANS: D 14. Bridge long 40xx feet, car speed 20 mile/hour, ask minuts (do not need exactly) to pass bridge (1 mile=51xx feet) A) 1 B) 2 C) 4 D) 5 E) 6 ANS B 15. xy=1 and x=3^(-4)*5^3, ask y (My first one) A) …… B) …… C) …… D) 3^(4)*5^(-3) E) …… ANS: D 16. right triangle OAB, O is (0,0), B (x, 0) and A (x,y), 角AOB=30度, OA长为１(* No use of this condition, may be let some stupid guy to calculate the number of x and y ???), ask y/x ANS: 3^(1/2)/3 17. ask | x-1| ? 1) | x-1| >1 2) | x|=1/3 ANS: C 18. sphere volume = (4/3)*PI*R^(3), two lead balls R=3 and R=6, melt and recast to a big ball ask R? ANS: 3*(9)^(1/3) 19. which of follow has root is 0, 1 and –1, A) x^3-1 B) x(x^2-1) C) x^3-x-1 D) …. E) …. ANS: B 20. in a share class, both 1st grade student 1/2, 4/5 of 1st grade students have no major, and 2nd grade students who has major is 3 times than that of 1st, ask 2nd have no major A) 1/5 B) 3/10 C) 2/5 D) ??? E) ??? ANS: B 21. New employee work 40 hours per week salary 24,000 per year( number like that), old employee works 60 hours with salary 40,000 per year. ASK ??? (forgot) 1) ???? 2) a number of something is 56,700 (maybe, can’t remember, need complementary) ANS: E 22. a guy’s week salary = BASE + commission where commission=(sale-3,200)*30%, ask salary 1) BASE=1600 2) Commission= 3 times of BASE ANS: C 23. which of following is greater than –5/4 A) –2 B) –3 C) –9/8 D) –4/3 E) –3/2 ANS: C 24 a farmer plant cotton and bean xxx (a real number) acres, 灌溉Cotton $40 per acre and bean $20 per acre. Ask number of acres plant cotton. 1) money cost for cotton is 20% greater than the cost of bean 2) total spend XXX (a real number) dollars ANS: D 25. ask (XY)^(1/2) integer?? 1) (X)^(1/2) is NOT a integer 2) (Y)^(1/2) is NOT a integer ANS: E 还有一些白痴题，不提也罢。 几点澄清： 1. 文字比较搞，大约６－７行，看了三遍没看懂（水平太低），最后理解为，四种sandwiches，Ｍ个students，前三个分成Ｍ份，第四个分成（Ｍ－４）份，Ｃ吃了４份，每种一份。问吃了占总数的多少。题目不难。现在想想应该(M-3)/M(M-4), 既 (3/m+1/(M-4))/4 3. L integer 7. 记错了，Ｘ应是３的等比数列。 多谢指正。