Peter invests a sum of money and gets back an amount of $ 815 in 3 years . David invests an equal amount of money and gets an amount of $854 in 4 years. If both amounts were invested at the same rate (simple interest ) What was the sum of money invested ? Choose one
A) 670	B) 664	C) 698	D) 744	E) 700
Since both Peter and David invested the same amount of money at the same rate, they would earn same interest per year.   David invested for one year more than Peter and hence he got interest amount for one more year.   Interest earned per year = Amount received by David - Amount received by Peter = 854 - 815= 
<gadget id="calculator">854 - 815</gadget>
<output>39</output>
39   Interest earned for 3 years= 39*3= 
<gadget id="calculator">39*3</gadget>
<output>117</output>
117   Amount invested= 815 - 117= 
<gadget id="calculator">815 - 117</gadget>
<output>698</output>
698   Answer: 698
<result>C</result>
Peter invests a sum of money and gets back an amount of $ 815 in 3 years . David invests an equal amount of money and gets an amount of $854 in 4 years. If both amounts were invested at the same rate (simple interest ) What was the sum of money invested ?