FF数学30套第一套问题

数学不好，请教几题：

Q12:B？

If n is an integer and 2 < n < 6, what is the value of n?

(1)     n is a factor of 15.

(2)     n is a factor of 21.

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.

Answer:

Q23

In the xy-plane, point (r, s) lies on a circle with center at the origin.  What is the value of r² + s²?

(1)     The circle has radius 2.

(2)     The point (√2, -√2) lies on the circle.

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.

Answer:

Q25:A

A photographer will arrange 6 people of 6 different heights for photograph by placing them in two rows of three so that each person in the first row is standing in front of someone in the second row.  The heights of the people within each row must increase from left to right, and each person in the second row must be taller than the person standing in front of him or her.  How many such arrangements of the 6 people are possible?

A.      5

B.      6

C.      9

D.     24

E.      36

Answer:

For any positive integer n, the sum of the first n positive integers equals [n(n+1)]/2.  What is the sum of all the even integers between 99 and 301?

A.      10,100

B.      20,200

C.      22,650

D.     40,200

E.      45,150

Answer:

Q30

Joanna bought only $0.15 stamps and $0.29 stamps.  How many $0.15 stamps did she buy?

(1)     She bought $4.40 worth of stamps.

(2)     She bought an equal number of $0.15 stamps and $0.29 stamps.

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.

Answer:

Q32

For a convention, a hotel charges a daily room rate of $120 for 1 person and x dollars for each additional person.  What is the charge for each additional person?

(1)   The daily cost per person for 4 people sharing the cost of a room equally is $45.

(2)   The daily cost per person for 2 people sharing the cost of a room equally is $25 more than the corresponding cost for 4 people.

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.

Answer:

Q35:C

What is the median number of employees assigned per project for the projects at Company Z?

(1)   25 percent of the projects at Company Z have 4 or more employees assigned to each project.

(2)   35 percent of the projects at Company Z have 2 or fewer employees assigned to each project.

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.

Answer: