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Bunuel
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A water tank had 3 taps. The first tap could fill the tank in 10 minu 22 Jun 2021, 03:45
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74% (02:36) correct 26% (02:46) wrong based on 175 sessions

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A water tank had 3 taps. The first tap could fill the tank in 10 minutes and the second tap could fill the tank in 15 minutes. When all the 3 taps were opened simultaneously, the tank was filled in 22 minutes. In how many minutes did the third tap fill or empty the tank?

(A) 6.50
(B) 8.25
(C) 9.27
(D) 15.67
(E) 18.50
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B
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A water tank had 3 taps. The first tap could fill the tank in 10 minu 22 Jun 2021, 03:55
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8.25 (B) Empty the tank

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A water tank had 3 taps. The first tap could fill the tank in 10 minu 22 Jun 2021, 04:17
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Explanation:

1/A + 1/B + 1/C = 1/22
1/10 + 1/15 + 1/C = 1/22
1/C = 1/22 - (3+2/30)
1/C = 1/22 - 1/6
1/C = 6 - 22 /132
1/C = -16/132
C = -8.25

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A water tank had 3 taps. The first tap could fill the tank in 10 minu 22 Jun 2021, 05:53
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Let the tank have a capacity of 330 units (LCM 10,15,22)

Then the efficiencies of the taps are 330/10 =+33 units , 330/15 =+22 units and let the effective work done when all 3 aps are working =

330/22 = 15 units(Hence we see its an effective positive work)

=>Working together, 33+22-x = 15 units of effective work is done every minute

=>x = 40 units of negative work every min and if this 3rd had to work alone it would empty the entire tank in 330/40 = 8.25 min

(option b)

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A water tank had 3 taps. The first tap could fill the tank in 10 minu 22 Jun 2021, 08:14
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Bunuel
A water tank had 3 taps. The first tap could fill the tank in 10 minutes and the second tap could fill the tank in 15 minutes. When all the 3 taps were opened simultaneously, the tank was filled in 22 minutes. In how many minutes did the third tap fill or empty the tank?

(A) 6.50
(B) 8.25
(C) 9.27
(D) 15.67
(E) 18.50
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Let the capacity of the tank be 330 units

Efficiency of tap A is 33
Efficiency of tap B is 22
Efficiency of tap A + B + C is 15

So, Efficiency of tap C is \(15 - (33 + 22) = -40\)

Hence time required to empty the tank is 330/40 = 8.25, Answer must be (B)
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A water tank had 3 taps. The first tap could fill the tank in 10 minu 15 Nov 2023, 23:53
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