Tap A and Tap B can fill up an empty tank in 4 hours.
Tap B and Tap C can fill up the same empty tank in 6 hours.
Tap A and Tap C can fill up the same empty tank in 3 hours.
How many hours will it take to fill up the empty tank if all the taps are turned on at the same time?
(1) 3/4 hours
(2) 3/8 hours
(3) 2 2/3 hours
(4) 6 1/2 hours
Source: Raffles Girls’ Primary