Question

A sum of money becomes 4 times at simple interest in 10 years. What is the rate of interest

Answer 1

let the principle be x.
therefore, 100 × 4 × x / 10 × x =40
hence the rate of interest is 40%

Answer 2

Answer:

30%

Explanation:

Let,sum of money= P+S.I;

N= 10 yrs;

S.I = P*N*R/100

R=?

from question,   P+S.I= 4*P

                  ==> P+(P*N*R/100)=4*P

                 ==> (P*10*R/100) = 4*P-P

                ==> (R/10)= (3*P)/P

              ==> R =30%