The simple Interest on a certain sum of money at the rate of 4% p.a. for 5 years is Rs. 1680. At what rate of interest the same amount of interest can be received on the same sum after 4 years ?	Choices
A) 5%	B) 6%	C) 8%	D) 4%	E) 7%
S.I. = 1680, R = 4% T = 5 years   Principal = (100 *1680)/ (5*4)= 
<gadget id="calculator">(100 *1680)/ (5*4)</gadget>
<output>8_400</output>
8400   So P= 8400   Rate = (100 *1680)/ (8400 * 4)= 
<gadget id="calculator">(100 *1680)/ (8400 * 4)</gadget>
<output>5</output>
5%   5%NSWER:5%
<result>A</result>
The simple Interest on a certain sum of money at the rate of 4% p.a. for 5 years is Rs. 1680. At what rate of interest the same amount of interest can be received on the same sum after 4 years ?