two pipes a and b can fill a tank in 6 and 12 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 / 6 part filled by b in 1 min . = 1 / 12 part filled by ( a + b ) in 1 min . = 1 / 6 + 1 / 12 = 1 / 4 . both the pipes can fill the tank in 4 minutes . answer : a"
add(multiply(6, const_100), multiply(multiply(subtract(const_1, multiply(add(divide(const_1, 6), divide(const_1, 12)), const_2)), 6), const_60))