Correct Answer: 15 hours
Explanation:
Then, second and third pipes will take (x -5) and (x - 9) hours respectively to fill the tank.
∴ | 1 | + | 1 | = | 1 |
x | (x - 5) | (x - 9) |
⟹ | x - 5 + x | = | 1 |
x(x - 5) | (x - 9) |
⟹ (2x - 5)(x - 9) = x(x - 5)
⟹ x2 - 18x + 45 = 0
(x - 15)(x - 3) = 0
⟹ x = 15. [neglecting x = 3]
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