Question

A tank can be filled by one pipe in four hours and by a second pipe in six hours; and when it is full, the tank can be drained by a third pipe in three hours. If the tank is empty and all three pipes are open, in how many hours will the tank be filled?

a. 8 hours
b. 12 hours
c. 24 hours

Answer 1

i think its a because the question says one pipe fills it in 4 hrs, then 2 pipes in 6 hrs, so 3 pipes in 8 hrs?!!?
is this ok?

Answer 2

I think maybe b

Explanation:

i might be wrong though message and i'll delete