Problem: if 40 % of ( x - y ) = 20 % of ( x + y ) , then what percent of x is y ?
Rationale: "40 % of ( x - y ) = 20 % of ( x + y ) 40 / 100 ( x - y ) = 20 / 100 ( x + y ) x = 3 y required percentage = y / x * 100 = y / 3 y * 100 = 33.3 % answer is d"
annotated_formula: multiply(divide(subtract(40, 20), add(40, 20)), const_100)