Question

A certain sum of money at compound interest becomes 7,396 in two years and
7,950.70 in three years. Find the rate of interest.​

Answer 1

Amount in 3years = Rs 7950.70 

Amount in 2 years= Rs 7396.00 

Interest for 3rd year =Rs 554.70 

Principal for 3rd year=Rs 7396 

Time = 1year 

Rate = (Interest *100)/ Principal*Time 

= 554.70*100 /7396* 1 

= 55470/ 7396 = 7.5% 

Let sum of money = x 

Amount = Rs 7396 

Time = 2 years 

then Amount = Principal(1+R/100)^T 

7396 = x (1+7.5/100)^2 

x =Rs 7396 /(43/40)^2 

=Rs 7396 *40*40 /43*43 

=Rs 6400