Sam and His New Pool

 

SAM the Butcher, on returning from his tour of cheese factories, arrived home to find he had an additional prize from his successful venture on TV. There in the backyard was a brand new glorious in-ground swimming pool! But before he could go in for a dip, he had to fill the pool, you see, water wasn't part of the prize. Sam, being his normal inquisitive self, decided to do some tests while filling the pool. He wanted to find out which of his taps would fill the pool the quickest. He noted that filling the pool from his backyard tap took 30 hours. Luckily, his prize pool was the top of the line model which included a plug hole for rapid emptying. Replacing the plug, he filled the pool again from his laundry tap, which took 20 hours. Emptying again, he decided to try using the tap in the front yard where he knew the water pressure was better. Running a hose to the back, he noted that it only took 12 hours to fill his pool. It was only after filling the pool for the third time that he noticed the pamphlet from the local Water Authority about saving every precious drop. Anyway, pleased with himself for finding the best tap with which to fill the pool, he finally dropped his daks and went in for a soak. While floating on his back with his belly nicely browning, he thought, "what if I'd used all three taps at the same time?". But he decided to try that out next summer. Assuming that the water pressure from a tap is not reduced when another tap is open, how long will it take (in hours, minutes and seconds) for Sam's pool to fill if all three taps are opened simultaneously?