A sum of money invested at compound interest to Rs. 800 in 3 years and to Rs 820 in 4 years. The
rate on interest per annum is.	Choose the most appropriate option.
A) 0.4 %
B) 5.0 %
C) 2.5 %
D) 7 %
E) 8 %

Rationale: explanation : s . i . on rs 800 for 1 year = 20 rate = ( 100 * 20 ) / ( 800 * 1 ) = 2.5 % answer : c
Answer: C