弱问GWD几道数学题。。。

半包茶叶

If p, s, and t are positive prime numbers, what is the value of p³s³t³ ?
(1)p³st = 728
(2)t = 13

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.


这题为什么选A啊？

Q14:
A certain pilot flew 400 miles to City K at an average speed of 350 miles per hour with the wind and made the trip back at an average speed of 250 miles per hour against the wind.Which of the following is closest to the pilot’s average speed, in miles per hour, for the round-trip?


A.280
B.290
C.300
D.310
E.320


答案为B 我选的C



Q32:
What is the probability that event E or event F or both will occur?
(1)The probability that event E will occur is 0.6.
(2)The probability that event F will occur is 0.4.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案为E 我选的C


Q36:
If x and y are integers, is y an even integer?
(1)2y – x = x² – y²
(2)x is an odd integer.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案为A 我选的C 貌似这种奇偶的问题我一直很纠结。。求思路。。。



Q6:
The function f is defined for each positive three-digit integer n by f(n) = 2^x 3^y 5^z, where x, y and z are the hundreds, tens, and units digits of n, respectively.If m and v are three-digit positive integers such that f(m) = 9 f(v), then m - v =


A.8
B.9
C.18
D.20
E.80
答案为D 我选对了，但是感觉思路不清晰。。求讲解、。



我很弱。。大家不要笑我。。求解。。。。。。鞠躬！！！





Q14:
A certain pilot flew 400 miles to City K at an average speed of 350 miles per hour with the wind and made the trip back at an average speed of 250 miles per hour against the wind.Which of the following is closest to the pilot’s average speed, in miles per hour, for the round-trip?


A.280
B.290
C.300
D.310
E.320


答案为B 我选的C



Q32:
What is the probability that event E or event F or both will occur?
(1)The probability that event E will occur is 0.6.
(2)The probability that event F will occur is 0.4.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案为E 我选的C


Q36:
If x and y are integers, is y an even integer?
(1)2y – x = x² – y²
(2)x is an odd integer.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案为A 我选的C 貌似这种奇偶的问题我一直很纠结。。求思路。。。



Q6:
The function f is defined for each positive three-digit integer n by f(n) = 2^x 3^y 5^z, where x, y and z are the hundreds, tens, and units digits of n, respectively.If m and v are three-digit positive integers such that f(m) = 9 f(v), then m - v =


A.8
B.9
C.18
D.20
E.80
答案为D 我选对了，但是感觉思路不清晰。。求讲解、。



我很弱。。大家不要笑我。。求解。。。。。。鞠躬！！！

wxq19881113

36题，化简为x^2+x=y^2+2y   x(x+1)=y(y+2)  ，无论x是奇数还是偶数，两个连续整数相乘的乘积都是偶数。所以y(y+2)是偶数。只有当y是偶数的时候，y(y+2)才是偶数。所以选A

wxq19881113

第一题，P^3*S*T=728   (PST)*P^2=728    728=13*7*4*2    那么，P^2=4  所以PST可以知道等于多少，自然p3s3t3 就知道等于多少了。

wxq19881113

14题楼主算错了吧，我算出来等于291.几。。。肯定选B啊。。

wxq19881113

32题好像貌似是没有给EF两个事件的关系，不知道是相关事件，还是无关事件，虽然两个条件相加他们出现的概率相加等于1。。。= =

wxq19881113

[attachimg=438,407]77452[/attachimg]

半包茶叶

14题楼主算错了吧，我算出来等于291.几。。。肯定选B啊。。

-- by 会员 wxq19881113 (2010/5/11 14:46:49)

    谢谢这位姐姐。。不过。。 291怎么算出来的啊？？

Jigoujigou

请问LZ这套题的Q18，怎么考虑啊？多谢！