Question

a sum of money lent on simple interest becomes 8/5 of itself in 4 years find the rate of interest per annum ​

Answer 1

Let the rate of interest =R

Let the initial sum =100

The sum becomes 8/5 of 100 =160

Interest earned =160-100=60

Interest =PRT/100

60= 100*R*4/100

60= 4R(interchangethe sides)

4R=60

R=15

So the rate of interest is 15%.

please mark me as the brainliest