Problema Solution

two pumps can fill a water tank in 256 minutes when working together. alone, the second pump takes 4 times as long as the first to fill the tank.

How many minutes would it take the first pump to fill the tank?

Answer provided by our tutors

Let , the time required for the first pump to fill the tank alone


So, time required for the 2nd pump to do it alone = 4X

Now, let the full tank = 1

Each pump will do a fraction of the job and will equal 1 when added together

256/X + 256/ 4X = 1

Or, [(256*4)+256]/4X =1

Or, 1024 + 256 = 4x

Or, 4X = 1280

Or, X = 320


So, the first pump will take 320 minutes to fill up the tank.