if 25 % of x is 30 less than 20 % of 1000 , then x is ?
"25 % of x = x / 4 ; 20 % of 1000 = 20 / 100 * 1000 = 200 given that , x / 4 = 200 - 30 = > x / 4 = 170 = > x = 680 . answer : d"
divide(subtract(multiply(1000, divide(20, const_100)), 30), divide(25, const_100))