Answer:
The pipe A will fill the pool in 2.25 hours and the pipe B will fill the pool in 1.75 hours.
Step-by-step explanation:
Pipe A alone can fill the pool in 4 hours.
So, in 1 hour it fills part of the pool.
and in 30 minutea it fills part of the pool.
If the pipe B is opened after 30 minutes the pipe A opened.
So, part of the pool is filled by both the pipe.
Again, pipe B alone fills the pool in 4 hours.
Hence, if both the pipes are open then they will fill in one hour part of the pool.
So, the remaining part of the pool will be filled by both the pipe in
hours i.e. 1.75 hours.
Therefore pipe A will fill the pool in (0.5 + 1.75) =2.25 hours and pipe B will fill the pool in 1.75 hours. (Answer)
