An amount at compound interest sums to Rs.17640/- in 2 years and to Rs.19404/- in 3 years at the same rate of interest. Find the rate percentage? Choose the correct choice from the following answers:
A) 5%	B) 7%	C) 9%	D) 10%	E) 12%
Explanation:   The difference of two successive amounts must be the simple interest in 1 year on the lower amount of money.   S.I = 19404/- - 17640/- = Rs. 1764/-   Rate of interest = (1764/17640) × (100/1)   =&gt;10%   Answer: Option 10%
<result>D</result>
An amount at compound interest sums to Rs.17640/- in 2 years and to Rs.19404/- in 3 years at the same rate of interest. Find the rate percentage?