If the simple interest on a sum of money for 2 years at 5% per annum is Rs.50, what is the compound interest on the same at the same rate and for the same time? Choose the correct choice from the following:
A) rs . 52 B) rs . 51.25 C) rs . 54.25 D) rs . 60 E) rs . 70

Rationale: "simple interest for 2 years = rs . 50 ie . for 1 years rs . 25 . . in the first year the s . i and c . i are same ie . rs . 25 . so in the 2 nd year in c . i calculated for 1 years interest also . so in second years for rs . 25 interest is 25 * 5 / 100 = 1.25 . so total c . p = 51.25 . answer : b"
Answer: B