Question

The rate of interest per annum would be .......... if sum of money amount to $Rs.10000$ after 3 years and $Rs.12000$ after 5 years at same rate.

• A. $16.6$%
• B. $17$%
• C. $18$%
• D. None

Answer 1

The correct option is A $16.6$%

SI for 2 years $=12000-1000=2000$
SI for 5 years$=\frac{2000}{3}\times 5=\frac{10000}{3}$
$P=10000-\frac{10000}{3}$
$P=\frac{20000}{3}$, $R=\frac{100\times 10000}{3\times \frac{20000}{3}\times 3}$
$R=\frac{100}{6}=16.66$