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? Options
A) $ 490	B) $ 500	C) $ 510	D) $ 520	E) $ 530

Rationale: "s . i for 5 years = $ 815 - $ 590 = $ 225 the s . i . is $ 45 / year s . i . for 2 years = $ 90 principal = $ 590 - $ 90 = $ 500 the answer is b ."
Answer: B