Q:

A) 2 hours | B) 8 hours |

C) 6 hours | D) 4 hours |

Answer: B) 8 hours

Explanation:

Explanation:

Efficiency of Inlet pipe A = 4.16% $\left(\frac{100}{24}\right)$

Efficiency of Inlet pipe B = 5.83% $\left(\frac{100}{{\displaystyle 17\frac{1}{7}}}\right)$

Therefore, Efficiency of A and B together = 100 %

Now, if the efficiency of outlet pipe be x% then in 10 hours the capacity of tank which will be filled = 10 * (10 - x)

Now, since this amount of water is being emptied by 'C' at x% per hour, then

$\frac{10x\left(10-x\right)}{x}=2.5hrs$

=> x = 8

Therefore, in 10 hours 20% tank is filled only. Hence, the remaining 80% of the capacity will be filled by pipes A and B in 80/10 = 8 hours