Q13

If the average (arithmetic mean) of the assessed values

of x houses is $212,000 and the average of the assessed

values of y other houses is $194,000, what is the average

of the assessed values of the x+y houses?

(1)   x+y=36

(2)   x=2y

     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:

Answer C

我怎么觉得选E啊？C求出来不是还有y么？

我怎么觉得是B

x+y个房子得平均值为 (212x+194y)/(x+y)

条件一求不出来

条件二x=2y，带入求得x+y个房子得平均直为203