GRE Prep Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Sep 28Live Online Class with Top GRE Expert Mike Butville
08:00 PM EDT
-10:00 PM EDT
Top scores are possible when you enroll in a powerful GRE course, taught live online + 6 months access to TTP GRE OnDemand video courses included! Class starts Mon/Wed Sept. 28, 2026 - Dec. 9, 2026, 8:00pm-10:00pm EST
Retired Moderator
Joined: 16 Apr 2020
Status:Founder & Quant Trainer
Affiliations: Prepster Education
Posts: 1546
Given Kudos: 172
Location: India
WE:Education (Education)
Tap A can fill a tank in 10 hours, tap B can fill it in 20 hours, and
[#permalink]
17 Aug 2021, 08:47
17 Aug 2021, 08:47
1
13
Bookmarks
00:00
Question Stats:
54% (02:44) correct
45% (02:55) wrong based on 42 sessions
Hide Show timer Statistics
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
[#permalink]
15 Oct 2025, 22:18
15 Oct 2025, 22:18
Hello from the GRE Prep Club BumpBot!
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.
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.
