# A certain sum of money at compound interest becomes Rs 7396 in 2 years and Rs 7950.70 in 3 years.Find the rate of interest?(PLs I REQUEST you for URGENT ans)?

Oct 14, 2016

Rate of interest is Rs 7.5%
let $x$ be the principal amount of money and $r$ be the rate of compound interest per anum.
We know the formula for final amount after $t$ years is $A = P \cdot {\left(1 + \frac{r}{100}\right)}^{t} \therefore 7396 = P \cdot {\left(1 + \frac{r}{100}\right)}^{2} \left(1\right) \mathmr{and} 7950.70 = P \cdot {\left(1 + \frac{r}{100}\right)}^{3} \left(2\right)$
Dividing equation (2) by equation (1) we get 7950.70/7396= (P*(1+r/100)^3)/ (P*(1+r/100)^2)=(1+r/100) or 1.075 =1 +r/100 or r/100=0.075 or r=0.075*100= 7.5= Rs 7.5%per anum [Ans]