Question

A sum is invested at compound interest becomes Rs 800 in 3 years and Rs 840 in 4 years .what is the rate of interest per annum ​

Answer 1

Answer:

Rate of interest=?

I¹=first consecutive year

I²=second consecutive year

=> R=(I²-I¹)/I¹ x 100

=> R= (840-800)/800 x 100

=> R=40/800 x 100

=> R=40/8

=> R=5%

Therefore, the rate of interest is 5% per annum

Answer 2

Step-by-step explanation:

rate interest=?

compound interest in 3 year =800

compound interest in 4 yesr =840

let, X=3year CI

Y=4year CI

R=(Y-X)/X×100

R=(840-800)/800×100

R=40/800×100

R=40/8

R=5

the rate of interest per annum is ,5%