What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years ?
(a)1 : 3
(b)1 : 4
(c)12 : 3
(d)Data inadequate
(e)None of these
Answer
Answer (as printed): C
Explanation
Let the principal be $P$ and rate of interest be $R \%$ ∴ Required ratio $=\left[\frac{\left(\frac{P \times R \times 6}{100}\right)}{\left(\frac{P \times R \times 9}{100}\right)}\right]=\frac{6 P R}{9 P R}=\frac{6}{9}=2: 3$.
Explanation as extracted from the printed page; notation may be imperfect.