A sum of money lent out at S.I. amounts to a total of $480 after 2 years and to $680 after a further period of 5 years. What was the initial sum of money that was invested?	Options:
A) $360	B) $380	C) $400	D) $420	E) $440
S.I for 5 years = $680 - $480 = $200   The S.I. is $40/year   S.I. for 2 years 680 -  480= 
<gadget id="calculator">680 -  480</gadget>
<output>200</output>
$200   The S.I. is $40/year   S.I. for 2 years= $80   Principal = $480 - $80 = $400   The answer is $400.480 -  80= 
<gadget id="calculator">480 -  80</gadget>
<output>400</output>
$400   The answer is $400.
<result>C</result>
A sum of money lent out at S.I. amounts to a total of $480 after 2 years and to $680 after a further period of 5 years. What was the initial sum of money that was invested?