Question

The SI on a sum of money for 4 years is Rs. $240$ and the CI on the sum at same rate for 2 years is Rs. $120$. The rate % p.a. is:

• A. $50$
• B. $100$
• C. $200$
• D. $300$

Answer 1

The correct option is B $100$

$SI=\frac{P\times r\times t}{100}$

$⟹240=\frac{P\times r\times 4}{100}⟹P=6000/r$

$CI=P\left[\right(1+\frac{r}{100}{)}^n-1]$

$⟹120=\left(6000/r\right)\left[\right(1+\frac{r}{100}{)}^2-1]$

Solving for $r$ we get,

$r=100\%$