#### mskmoorthy

##### Well-known member

There are four taps of water (let us call them A, B, C and D) and a Bucket. Tap A by itsef can fill the Bucket in one hour. Tap B by itself can fill the Bucket in 30 minutes. Tap C by itself can fill the Bucket in 20 mintes. Tap D by itself can fill the Bucket in 15 minutes.

Question: How long will it take to fill the Bucket with all four taps running.