Question

A sum of Rs 1,550 was lent partly at 5% per annum and partly at 8% per annum simple interest. The total interest received after 3 years is Rs 300. Find the ratio of money lent at 5% to that at 8%?

• A. 6:5
• B. 5:6
• C. 15:16
• D. 16:15

Answer 1

Answer: (D)

16:15

$t_1=3,r_1=5,P_1=?,S{I}_1$
$t_2=3,r_2=8,P_2=?,S{I}_2$
$P_1+P_2=1,550$
$S{I}_1+S{I}_2=300$
or $\frac{P_1{t}_1{r}_1}{100}+\frac{P_2{t}_2{r}_2}{100}=300$
or $\frac{P_1\times 3\times 5}{100}+\frac{P_2\times 8\times 3}{100}=300$
or $\frac{3}{100}(5P_1+8P_2)=100$
$or5P_1+8P_2=10,000$
or $(P_1+P_2=1,500)\times 5$
or $5P_1+8P_2=10,000$
or $5P_1+5P_2=7,750$
or $3P_2=2,250$
$\therefore P_2=750$ and $P_1=800$
Hence, $P_1:P_2=800:750=16:15$