Two pipes are connected to the pool, the first pipe fills the pool in 8 hours, and together both

Two pipes are connected to the pool, the first pipe fills the pool in 8 hours, and together both fills in 4 4/9 hours. How many hours does the second pipe take to fill the pool?

Let’s find out what part of the pool the first pipe can fill in 60 minutes.

It is known from the problem statement that the first pipe fills the entire pool in 8 hours, therefore, in 60 minutes this pipe will fill 1/8 of the pool.

Find out which part of the pool two pipes fill in 60 minutes.

From the condition of the problem it is known that two pipes can fill the entire pool in 4 4/9 hours, which means that in 60 minutes two pipes will fill 1 / (4 + 4/9) = 1 / (40/9) = 9/40 part of the pool …

Then the second pipe in 60 minutes can fill 9/40 – 1/8 = 1/10 of the pool, and the entire pool can fill in ten hours.

Answer: The 2nd pipe can fill the entire pool in ten hours.