Q10:

If $1,000 will be deposited in a bank account and I is the dollar amount of interest earned from the original deposit, represented as I = 1000 {(1 + r/100)ⁿ – 1}, and the annual interest rate is r percent, is r > 8 percent?

(1) The deposit earns a total of $210 in interest in the first 2 years.

(2) (1 + r/100)² > 1.15

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.

key: D. But I think it is B. condition (2) cannot prove that r>8.

支持condition (2) cannot prove that r>8.either r>8 or r<8

所以答案为A

题目是问 if r>8% 即 if r>0.08 ，不是8哦。从这点看（2）条件也满足。选D

还是认为不应选D,因为条件（2）解出r为7.几%,无法判定r>0.08.只能作为必要条件，不是充分条件。

而题目意思是要求充分条件。所以（2）是不正确的