Question

at a constant rate of flow, it takes 20 minutes to fill a swimming pool if a large hose is used and 30 minutes if a small hose is used. at these constant rates, how many minutes will it take to fill the pool when both hoses are used simultaneously?

Answer 1

Let's pipe A fill 30 minute and B is 20 minute than Take capacity is lcm of 30and20 is 60 Than A is fill in one minute 2 unit And B is fill in one minute 3 unit Than A+B =5 units Total fill units 60 Than 60/5=12 minutes in fill tank