UPSC CDS Math Work, Time and Unitary Method Questions

Let the time taken by pipe C to empty the tank be t minutes.
Suppose the capacity of the tank be V units
Therefore, amount of tank filled by pipe A in 50 minutes + Amount of tank filled by pipe B in 50 minutes – Amount of tank emptied by pipe Cin 50 minutes = V
⇒

50

t

=

5

6

+

2

3

−1=

1

2

⇒ t = 100 minutes
Thus, pipe C will empty the tank in 100 minutes