Question

At what rate of interest per annum will
a sum double itself in 8 years at SI?​

Answer 1

Answer:

12.5% per annum

Step-by-step explanation:

let the initial amount of money invested be = Rs. X

after 2 years the money will became = 2X

initial amount invested = 2X-X=X

let the rate of interest be = r

=> S.I. = PRT/100

=> x = xr(8)/100

=> r = 100/8 = 12.5

hence the rate of interest at which a sum will double itself in 8 years is 12.5% per annum