A sum of money invested at compound interest to Rs. 800 in 3 years and to Rs 840 in 4 years. The
rate on interest per annum is.	Choose the most appropriate option:
A) 4%	B) 5%	C) 6%	D) 7%	E) 8%
Explanation:   S.I. on Rs 800 for 1 year = 40   Rate = (100*40)/(800*1)= 
<gadget id="calculator">(100*40)/(800*1)</gadget>
<output>5</output>
5%   Answer: 5%
<result>B</result>
A sum of money invested at compound interest to Rs. 800 in 3 years and to Rs 840 in 4 years. The
rate on interest per annum is.