【正确答案】 C

【答案解析】In order to calculate 15 percent of 90, multiply 90 by 0.15, the decimal equivalent of 15%. Likewise, to calculate 90 percent of 15, multiply 15 by 0.90, the decimal equivalent of 90 percent:
(0.15)(90)=13.5
(0.90)(15)=13.5
The quantities are equal.