two numbers are respectively 20 % and 50 % more than a third number . what percentage is the first of the second ?
"required answer = ( 100 + x ) / ( 100 + y ) * 100 = 120 * 100 / 150 = 80 % answer is c"
subtract(const_100, multiply(divide(add(20, const_100), add(50, const_100)), const_100))