Task: Question Answering
Input (English): Problem: find the compound interest on $ 50000 in 2 years at 4 % per annum , the interest being compounded half - yearly ? 
Options: a ) $ 645.56 , b ) $ 4121.60 , c ) $ 954.26 , d ) $ 745.69 , e ) $ 1020.45
Output (English): b