Question

A certain serum will be doubled in 15 years on simple interest ayi the rate?

Answer 1

We know that the formula of Simple Interest is
S.I. = P×R×T/100
And here, A certain sum of money is doubled in 15 years.
So,Let, Rs. x be the principal
And, R% be the rate of interest
Therefore, S.I. = 2x - x = Rs. x
x = x*R*15/100
x/x = 15R/100
And hence, R= 100/15
R= 20/3%