Two pipes A and B can fill a tank in 17 and 34 minutes respectively. If third pipe 'C' is also joined then all three pipes can fill it in \(\frac{68}{7}\) minutes. Find the time taken by C to fill the tank alone.
Answer & explanation
Correct answer: option 3

Efficiency of C = efficiency of (A + B + C) - efficiency of (A + B)
= 7 - 4 - 2 = 1
C will fill it in = \(\frac{68}{1}\) = 68 minutes