Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
|
|
GMAT 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.
Dec 1310:00 AM EST
-12:00 PM EST
Have you ever wondered how to score a PERFECT 805 on the GMAT? Meet Julia, a banking professional who used the Target Test Prep course to achieve this incredible feat. Julia's story is nothing short of an inspiration.
Dec 1410:00 AM EST
-12:00 PM EST
Think a 100% GMAT Verbal score is out of your reach? Target Test Prep will make you think again! Our course uses techniques such as topical study and spaced repetition to maximize knowledge retention and make studying simple and fun.
Dec 1411:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test.- Dec 15
11:00 AM IST
-01:00 PM IST
Attend this free GMAT Algebra Webinar and learn how to master the most challenging Inequalities and Absolute Value problems with ease. 
Dec 1608:00 AM PST
-11:59 PM PST
GMAT Club 12 Days of Christmas is a 4th Annual GMAT Club Winter Competition based on solving questions. This is the Winter GMAT competition on GMAT Club with an amazing opportunity to win over $40,000 worth of prizes!
04 Feb 2021, 04:00
Kudos
Bookmarks
A
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
95%
(hard)
Question Stats:
24% (03:38) correct
76%
(03:20)
wrong
based on 38
sessions
History
Date
Time
Result
Not Attempted Yet
Taps A and C can fill a tank in 5 and 7 hrs respectively. Taps B and D can drain a full tank in 6 and 8 hrs. Respectively. Taps A and B are opened at 6 a.m. and6.30 a. m. respectively, till 65% of the tank is filled. Then, C and D are also opened. At what time will the tank get filled?
A. 1025/43 hrs
B. 1134/43 hrs
C. 1249/43 hrs
D. 1312/43 hrs
E. 1345/43 hrs
A. 1025/43 hrs
B. 1134/43 hrs
C. 1249/43 hrs
D. 1312/43 hrs
E. 1345/43 hrs
04 Feb 2021, 04:17
Kudos
Bookmarks
Bunuel
Taps A and C can fill a tank in 5 and 7 hrs respectively. Taps B and D can drain a full tank in 6 and 8 hrs. Respectively. Taps A and B are opened at 6 a.m. and6.30 a. m. respectively, till 65% of the tank is filled. Then, C and D are also opened. At what time will the tank get filled?
A. 1025/43 hrs
B. 1134/43 hrs
C. 1249/43 hrs
D. 1312/43 hrs
E. 1345/43 hrs
A. 1025/43 hrs
B. 1134/43 hrs
C. 1249/43 hrs
D. 1312/43 hrs
E. 1345/43 hrs
Let, Tank capacity.= LCM (5, 7, 6, 8) units = 840 Units
Work done by Tap A in 1 hours \(= \frac{840}{5} = +168\) units
Work done by Tap C in 1 hours \(= \frac{840}{7} = +120\) units
Work done by Tap B in 1 hours \(= \frac{840}{6} = -140\) units
Work done by Tap D in 1 hours \(= \frac{840}{8} = -105\) units
65% of tank capacity = 65% of 840 = 546 units
Tap A works alone from 6 to 6:30 AM hence it does work = 168/2 = 84 units
Remaining work = 546-84 = 462
Tap A and B's combined work of every hour = 168-140 = 28 units
Remaining time = 462/28 = 16.5 hours
Remaining work = 35% of tank = 294 units
Combines work of A, B C and D = 168+120-140-105 = 43 units
Remaining time = 294/43 hours \(= 6 \frac{36}{43}\) hours
Total Time (after 6 AM) \(= 0.5 + 16.5+6 \frac{36}{43} = 23 \frac{36}{43} = \frac{1025}{43}\)
Answer: Option A
Two MUST join YouTube channels for GMAT aspirant GMATinsight (1000+ FREE Videos) and GMATclub
For a Comprehensive Topicwise Quant Video course at an affordable price CLICK HERE
General Discussion
19 Feb 2021, 04:51
Kudos
Bookmarks
Bunuel
Taps A and C can fill a tank in 5 and 7 hrs respectively. Taps B and D can drain a full tank in 6 and 8 hrs. Respectively. Taps A and B are opened at 6 a.m. and6.30 a. m. respectively, till 65% of the tank is filled. Then, C and D are also opened. At what time will the tank get filled?
A. 1025/43 hrs
B. 1134/43 hrs
C. 1249/43 hrs
D. 1312/43 hrs
E. 1345/43 hrs
Solution:A. 1025/43 hrs
B. 1134/43 hrs
C. 1249/43 hrs
D. 1312/43 hrs
E. 1345/43 hrs
The rates of taps A, B, C, and D are 1/5, 1/6, 1/7, and 1/8, respectively.
We can let x be the number of hours tap A is open until 65% of the tank is filled. Thus, tap B is open for (x - 1/2) hours, and we can create the equation:
(1/5)(x) - (1/6)(x - 1/2) = 65/100
x/5 - x/6 + 1/12 = 13/20
Multiplying the equation by 60, we have:
12x - 10x + 5 = 39
2x = 34
x = 17
Since C and D are opened when the tank is 65% filled (after A has been operating for 17 hours, B has been operating for 16 1/2 hours, and both A and B will remain open until the tank is filled), we can create an equation where y is the number of hours needed to fill the remaining 35% of the tank:
y(1/5 - 1/6 + 1/7 - 1/8) = 35/100
y(1/30 + 1/56) = 7/20
86y/(30 * 56) = 7/20
y = (7 * 30 * 56)/(20 * 86)
y = (7 * 3 * 14)/43 = 294/43
Therefore, it takes 17 + 294/43 = (731 + 294)/43 = 1025/43 hours to fill the tank completely.
Answer: A
