Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest is  Choose one
A) Rs 1650 B) Rs 1750 C) Rs 1850 D) Rs 1950 E) None of these
Explanation:   C.I.=(4000×(1+10/100)2−4000)   =4000∗11/10∗11/10−4000=840   So S.I. = 840/2= 
<gadget id="calculator">840/2</gadget>
<output>420</output>
420   So Sum= S.I.∗100/R∗T=420∗100/3∗8=Rs1750   Option Rs 1750
<result>B</result>
Simple interest on a certain sum of money for 3 years at 8% per annum is half the compound interest on Rs. 4000 for 2 years at 10% per annum. The sum placed on simple interest is