Simple interest on a sum for 5 years is equal to 20 percent of the principal. In how many years interest will be equal to the principal?

Correct option is C

Given:
Principal = P
Time = 5 years
Simple Interest (SI) = 20% of Principal
Formula Used:
Simple Interest = (P × R × T) / 100
Solution:
SI = 20% of Principal.
SI = (P × R × 5) / 100 = 0.2P
R = 4%.
when the interest is equal to the principal, i.e., SI = P.
P = (P × 4 × T) / 100
T = 25 years