Time taken to fill the pool by faucet:
A-2 days
B-3 days
C-4 days
D-6 hours=6/24=1/4 days
Thus the time taken for the 4 faucets working together to fill the pool will be the GCD of the time taken by the 4, which will be:
GCD(2,3,4,0.25)
=1
=1 day
Answer: 1 day or 24 hours