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Tap A can fill a tank in 10 hours, tap B can fill it in 20 hours, and
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17 Aug 2021, 08:47
17 Aug 2021, 08:47
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Question Stats:
53% (02:44) correct
46% (02:53) wrong based on 43 sessions
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Tap A can fill a tank in 10 hours, tap B can fill it in 20 hours, and, an outlet, Tap C, can empty the tank in 30 hours. Each tap is opened, one by one, for exactly one hour and then closed and the order continues (A, B, C, A, B, C, A, ...) till the tank overflows.
A. Quantity A is greater
B. Quantity B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
Quantity A |
Quantity B |
Time required to make a tank overflow, which is filled upto \(\frac{1}{4}^{th}\) of its total capacity |
18 hours |
A. Quantity A is greater
B. Quantity B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Given Kudos: 172
Location: India
WE:Education (Education)
Re: Tap A can fill a tank in 10 hours, tap B can fill it in 20 hours, and
[#permalink]
19 Aug 2021, 01:45
19 Aug 2021, 01:45
5
Explanation:
Let total capacity of the tank be \(60\) units.
If, \(\frac{1}{4}^{th}\) of the tank in already filled, we need to will rest of the tank i.e. \(\frac{3}{4}(60) = 45\) units
In \(1\) hour,
Work by A = \(\frac{60}{10} = 6\) units
Work by B = \(\frac{60}{20} = 3\) units
Work by C = \(\frac{60}{30} = -2\) units
NOTE: -ve sign indicates opposite work
\(7\) units of tank can be filled in \(3\) hours and at the same rate we can fill \(42\) units in \(6(3) = 18\) hours
Now, we need to fill \(3\) units using tap A
If tap A can fill \(6\) units of this tank in \(1\) hour then, it will take \(0.5\) hours to fill \(3\) units.
Col. A: 18 + 0.5 = 18.5 Hours
Col. B: 18 hours
Hence, option A
Let total capacity of the tank be \(60\) units.
If, \(\frac{1}{4}^{th}\) of the tank in already filled, we need to will rest of the tank i.e. \(\frac{3}{4}(60) = 45\) units
In \(1\) hour,
Work by A = \(\frac{60}{10} = 6\) units
Work by B = \(\frac{60}{20} = 3\) units
Work by C = \(\frac{60}{30} = -2\) units
NOTE: -ve sign indicates opposite work
\(7\) units of tank can be filled in \(3\) hours and at the same rate we can fill \(42\) units in \(6(3) = 18\) hours
Now, we need to fill \(3\) units using tap A
If tap A can fill \(6\) units of this tank in \(1\) hour then, it will take \(0.5\) hours to fill \(3\) units.
Col. A: 18 + 0.5 = 18.5 Hours
Col. B: 18 hours
Hence, option A
General Discussion
Re: Tap A can fill a tank in 10 hours, tap B can fill it in 20 hours, and
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15 Oct 2025, 22:18
15 Oct 2025, 22:18
Hello from the GRE Prep Club BumpBot!
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Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
