if 50 % of ( x - y ) = 20 % of ( x + y ) , then what percent of x is y ?
"50 % of ( x - y ) = 20 % of ( x + y ) 50 / 100 ( x - y ) = 20 / 100 ( x + y ) 3 x = 7 y required percentage = y / x * 100 = 3 y / 7 y * 100 = 42.85 % answer is b"
multiply(divide(subtract(50, 20), add(50, 20)), const_100)