A swimming pool has four faucets. The first can fill the entire pool with water in two days, the second - in three days, the third - in four days and the last one can fill the pool in 6 hours. How long will it take to fill the pool using all 4 faucets together?

Given:

Faucet one fills the pool in 2 days = 48 hours

Faucet two fills the pool in 3 days = 72 hours

Faucet three fills the pool in 4 days = 96 hours

Faucet one fills the pool in 6 hours.

The first faucet takes 48 hours to fill the pool

∴ In one hour it fills of the pool
Similarly,

The second faucet
The third faucet
And the fourth faucet fills of the pool
We need to add all those fractions together:

So, in one hour the pool will be full
And it will be completely full in

= 4 hours 43 minutes and 17 seconds.