The amount of principal Rs.8000 at compound interest at the ratio of 5% p.a. for 1 year is  Pick one:  A) s . 9621  B) s . 6921  C) s . 8400  D) s . 6261  E) s . 6361

Rationale: "c . i = p ( 1 + r / 100 ) ^ n = 8000 ( 1 + 5 / 100 ) = rs 8400 answer : c"
Answer: C