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? Pick.
A) 5 % B) 7 % C) 9 % D) 10 % E) 12 %
<gadget id="calculator">19_404 - 17_640</gadget>
<output>1_764</output>

<gadget id="calculator">1_764 / 17_640</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) * 100</gadget>
<output>10</output>

<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?
multiply(divide(subtract(19404, 17640), 17640), const_100)
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 ) = > 10 % answer : option d