Question

simple interest on a sum of money is 1/3 rd of the sum itself and number of years is thrice the rate per cent.find the rate of interest.

Answer 1

Let the sum of money (principal) = P
So, SI = 1/3P
Let the rate be R
So, Time = 3R
As, SI = PRT/100
So, 1/3P = P*R*3R/100
So, solving this equation:

1/3P = P*R*3R/100
1/3 = 3R^2 (P is divided on both sides. This leaves us with
1/3 = 3R square OR 3R^2/100
So, R^2 = 100/9
So, R = Square root of 100/9 = 10/3

Answer:The rate of interest is 10/3%

Please correct me if I am wrong.
Hope it helps!