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

Simple interest on a sum for 5 years is equal to 20% of the principal.

1.	Simple interest on a sum for 5 years is equal to 20% of the principal. In how many years interest will be equal to the principal?
A.	20
B.	25
C.	15
D.	16
Answer» C. 15