two pipes a and b can fill a tank in 40 and 120 minutes respectively . if both the pipes are used together , then how long will it take to fill the tank ?
"part filled by a in 1 min . = 1 / 40 part filled by b in 1 min . = 1 / 120 part filled by ( a + b ) in 1 min . = 1 / 40 + 1 / 120 = 1 / 30 . both the pipes can fill the tank in 30 minutes . answer : a"
add(multiply(40, const_100), multiply(multiply(subtract(const_1, multiply(add(divide(const_1, 40), divide(const_1, 120)), const_2)), 40), const_60))