tt19-10

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

这道题选D,是不是因为R>8%,若是R>8,条件2就错了,因为,r=7.9, 也会有(1 + r/100)² > 1.15

这种题目不用硬算的，只要看能不能回答结果就好了，能回答的就是对的，不能的就是错的

第一个是个固定的，肯定能算出来R，所以不管怎么样都是可以的

第二个是不等式，要算一下R的范围才行