Question

If a sum when placed at compound interest grows to Rs. 6,400 in 2 years and to Rs. 8,000 in 3 years, find the rate of interest per annum.​

Answer 1

Step-by-step explanation:

let the "simple intrest on principle be

8000 - 6400 = 1600

for 1 year

To find principle

6400 - 1600 ×2 (because N = 2 )

= 6400 - 3200

therefore

PRINCIPLE = 3200

TO FIND RATE

R = P × T

100 × I

R = 3200 × 2

3200 x 100

Therefore rate = 50 %