A sum of money invested at compound interest to Rs. 800 in 3 years and to Rs 880 in 4 years. The
rate on interest per annum is.  Pick one:	A) 4%	B) 5%	C) 6%	D) 7%	E) 10%
Explanation:   S.I. on Rs 800 for 1 year = 80   Rate = (100*80)/(800*1)= 
<gadget id="calculator">(100*80)/(800*1)</gadget>
<output>10</output>
10%   Answer: 10%
<result>E</result>
A sum of money invested at compound interest to Rs. 800 in 3 years and to Rs 880 in 4 years. The
rate on interest per annum is.