if 50 % of ( x - y ) = 40 % of ( x + y ) then what percent of x is y ?
"50 % of ( x - y ) = 40 % of ( x + y ) ( 50 / 100 ) ( x - y ) = ( 40 / 100 ) ( x + y ) 5 ( x - y ) = 4 ( x + y ) x = 9 y x = 9 y therefore required percentage = ( ( y / x ) x 100 ) % = ( ( y / 9 y ) x 100 ) = 11 % answer is b ."
multiply(divide(subtract(50, 40), add(50, 40)), const_100)