gre the total interest earned on d dollors invested for 3 mo

題目：

gre
the total interest earned on d dollors invested for 3 months at 11 percent simple annual interest

解答：

就是問你如果是年利率單利爲11%的3個月的利息收入.
其實就是換算一下,把年利率/4就是月利率,看你題目里,本金用d代表了,就是d*11%/4*3