求助数学

xiahuistacy

有几个数学题目不明白 ,要二战了,请大家帮忙!谢谢
1。

A researcher plans to identify each participant in a certain medical experiment with a code consisting of either a single letter or a pair of distinct letters written in alphabetic order.  What is the least number of letters that can be used if there are 12 participants, and each participant is to receive a different code?



A.    4

B.     5

C.     6

D.    7

E.     8

这个题目完全不知道怎么下手,答案是B

2   Was the average (arithmetic mean) weight of the package mailed at a certain post office yesterday greater than 600 grams?(1)   The total weight of the packages mailed at the post office yesterday was greater than 14,500 grams.

(2)     Fewer than 25 packages were mailed at the post office yesterday.

                 

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.

这个题目答案C 但是我觉得应该是E



3 Working simultaneously and independently at an identical constant rate, 4 machines of a certain type can produce a total of x units of product P
in 6 days.  How many of these machines, working simultaneously and independently at this constant rate, can produce a total of 3x units of product P in 4 days?


A.    24

B.     18

C.     16

D.    12

E.     8

这个题目好难啊，不知道怎么着手。答案是B

4 For any integers x and y
, min(x, y) and max(x, y) denote the minimum and the maximum of x and y, respectively.  For example, min(5, 2) = 2 and max(5, 2) = 5.  For the integer w, what is the value of min(10, w) ?
(1)     w = max(20, z
) for some integer z.
(2)     w = max(10, w
)
                 

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.

这个题目选D 但是我觉得是C

5  If 9x = 27^y, which of the following expresses x
in terms of y ?


A.    3^y

B.     3^{y - 1}

C.     3^{2y -} 1

D.    3^2y - 3

E.     3^3y - 2



答案是E 但是我觉得是 A



6

If the range of the six numbers 4, 3, 14, 7, 10, and x is 12, what is the difference between the greatest possible value of x
and least possible value of x ?


A.    0

B.     2

C.     12

D.    13

E.     15

答案是D 但是我认为是A



7

Does the decimal equivalent of
, where p and q are positive integers, contain only a finite number of nonzero digits?
(1)     p > q

(2)     q = 8

                 

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.

选B 但是我错选了E

4 For any integers x and y
, min(x, y) and max(x, y) denote the minimum and the maximum of x and y, respectively.  For example, min(5, 2) = 2 and max(5, 2) = 5.  For the integer w, what is the value of min(10, w) ?
(1)     w = max(20, z
) for some integer z.
(2)     w = max(10, w
)
                 

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.

这个题目选D 但是我觉得是C

5  If 9x = 27^y, which of the following expresses x
in terms of y ?


A.    3^y

B.     3^{y - 1}

C.     3^{2y -} 1

D.    3^2y - 3

E.     3^3y - 2



答案是E 但是我觉得是 A



6

If the range of the six numbers 4, 3, 14, 7, 10, and x is 12, what is the difference between the greatest possible value of x
and least possible value of x ?


A.    0

B.     2

C.     12

D.    13

E.     15

答案是D 但是我认为是A



7

Does the decimal equivalent of
, where p and q are positive integers, contain only a finite number of nonzero digits?
(1)     p > q

(2)     q = 8

                 

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.

选B 但是我错选了E



(1)   The total weight of the packages mailed at the post office yesterday was greater than 14,500 grams.

(2)     Fewer than 25 packages were mailed at the post office yesterday.

                 

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.

这个题目答案C 但是我觉得应该是E



3 Working simultaneously and independently at an identical constant rate, 4 machines of a certain type can produce a total of x units of product P
in 6 days.  How many of these machines, working simultaneously and independently at this constant rate, can produce a total of 3x units of product P in 4 days?


A.    24

B.     18

C.     16

D.    12

E.     8

这个题目好难啊，不知道怎么着手。答案是B

4 For any integers x and y
, min(x, y) and max(x, y) denote the minimum and the maximum of x and y, respectively.  For example, min(5, 2) = 2 and max(5, 2) = 5.  For the integer w, what is the value of min(10, w) ?
(1)     w = max(20, z
) for some integer z.
(2)     w = max(10, w
)
                 

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.

这个题目选D 但是我觉得是C

5  If 9x = 27^y, which of the following expresses x
in terms of y ?


A.    3^y

B.     3^{y - 1}

C.     3^{2y -} 1

D.    3^2y - 3

E.     3^3y - 2



答案是E 但是我觉得是 A



6

If the range of the six numbers 4, 3, 14, 7, 10, and x is 12, what is the difference between the greatest possible value of x
and least possible value of x ?


A.    0

B.     2

C.     12

D.    13

E.     15

答案是D 但是我认为是A



7

Does the decimal equivalent of
, where p and q are positive integers, contain only a finite number of nonzero digits?
(1)     p > q

(2)     q = 8

                 

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.

选B 但是我错选了E

4 For any integers x and y
, min(x, y) and max(x, y) denote the minimum and the maximum of x and y, respectively.  For example, min(5, 2) = 2 and max(5, 2) = 5.  For the integer w, what is the value of min(10, w) ?
(1)     w = max(20, z
) for some integer z.
(2)     w = max(10, w
)
                 

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.

这个题目选D 但是我觉得是C

5  If 9x = 27^y, which of the following expresses x
in terms of y ?


A.    3^y

B.     3^{y - 1}

C.     3^{2y -} 1

D.    3^2y - 3

E.     3^3y - 2



答案是E 但是我觉得是 A



6

If the range of the six numbers 4, 3, 14, 7, 10, and x is 12, what is the difference between the greatest possible value of x
and least possible value of x ?


A.    0

B.     2

C.     12

D.    13

E.     15

答案是D 但是我认为是A



7

Does the decimal equivalent of
, where p and q are positive integers, contain only a finite number of nonzero digits?
(1)     p > q

(2)     q = 8

                 

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.

选B 但是我错选了E

xiahuistacy

我也不知道为什么发上来就这么混乱了  不好意思啊 我编辑的时候明明只编辑了一次

xiahuistacy

总共是7个题目 唉 ！！！！！！！！！！！