SSC CPO 2023 PYQ — Question 145

The correct answer is option 2 i.e $38\frac{10}{49}$h.

Given:

Time taken by first pipe = 12 hours

Time taken by second pipe = 16 hours

Concept used:

Work done = efficiency × time

Calculations:

Total work done (LCM of 12 and 16) = 48 units

Efficiency of first pipe = $48\over 12$ = 4

Efficiency of second pipe = $48 \over 16$ = 3

Total efficiency = 7

Time taken by 1st and 2nd pipe together = $48 \over 7$ hours

Time taken due to leakage by both pipes = $48 \over 7$ + $3 \over 2$ = $117 \over 14$ hours

Required time taken = [${48 \times 14} \over 117$] - 7 = $1872 \over 49$

⇒ $38\frac{10}{49}$ h