a number is increased by 20 % and then decreased by 20 % . find the net increase or decrease per cent .
"let the number be 100 . increase in the number = 20 % = 20 % of 100 = ( 20 / 100 ã — 100 ) = 20 therefore , increased number = 100 + 20 = 120 this number is decreased by 20 % therefore , decrease in number = 20 % of 120 = ( 20 / 100 ã — 120 ) = 2400 / 100 = 24 therefore , new number = 120 - 24 = 96 thus , net decreases = 100 - 96 = 4 hence , net percentage decrease = ( 4 / 100 ã — 100 ) % = ( 400 / 100 ) % = 4 % answer : e"
divide(multiply(add(20, const_100), subtract(const_100, 20)), const_100)