a , b and c can do a piece of work in 24 , 30 and 40 days respectively . they start the work together but c leaves 4 days before the completion of the work . in how many days is the work done ?
x / 24 + x / 30 + x / 40 = 1 x = 11 days answer : d
add(subtract(subtract(24, subtract(40, 30)), 4), const_1)