A sum of money lent out at S.I. amounts to a total of $590 after 2 years and to $815 after a further period of 5 years. What was the initial sum of money that was invested?	Pick one.
A) $490  B) $500  C) $510  D) $520  E) $530
S.I for 5 years = $815 - $590 = $225   The S.I. is $45/year   S.I. for 2 years 815 -  590= 
<gadget id="calculator">815 -  590</gadget>
<output>225</output>
$225   The S.I. is $45/year   S.I. for 2 years= $90   Principal = $590 - $90 = $500   The answer is $500.590 -  90= 
<gadget id="calculator">590 -  90</gadget>
<output>500</output>
$500   The answer is $500.
<result>B</result>
A sum of money lent out at S.I. amounts to a total of $590 after 2 years and to $815 after a further period of 5 years. What was the initial sum of money that was invested?