Task: Question Answering
Input (English): Problem: 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
Output (English): b