[求助] 数学题

Henrik

The annual interest rate earned by an investment increased by 10 percent from last year to this year. If the annual interest raste earned by the investment this year was 1 percent, what was the annual interest rate last year?

9.1%

读不明白问题

naonao7949

0.91%? OR 10% FOR THIS YEAR...SOMETHING WRONG HERE

chen_fu2001

設本金P 去年利率=R   今年利率=1.1R

{P(1+R)(1+1.1R)-P(1+R)}/P(1+R)(1+1.1R)=1.1R/1+1.1R=0.01

R=0.0091=0.91%

Henrik

明白了. 谢谢