Task: Question Answering
Input (English): Problem: the difference between the compound interest and simple interest on a certain sum of money at 5 % per annum for 2 years is 45 . then the original sum is ? 
Options: a ) rs . 16500 / - , b ) rs . 17000 / - , c ) rs . 18000 / - , d ) rs . 19000 / - , e ) rs . 20000 / -
Output (English): c