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!
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
75%
(hard)
Question Stats:
48% (02:25) correct
52%
(02:09)
wrong
based on 66
sessions
History
Date
Time
Result
Not Attempted Yet
A and B are friends. A and B can independently build a wall in 15 days and 10 days respectively. A and B started building the wall, but A left 3 days before the work was completed. In how many days was the wall built?
A. 5 days
B. 6 days
C. 36/5 days
D. 8 days
E. 42/5 days
A. 5 days
B. 6 days
C. 36/5 days
D. 8 days
E. 42/5 days
17 Apr 2022, 05:24
Kudos
Bookmarks
Bunuel , answer to this question should be 8 days i.e. Option D.
Please check.
As both can complete the work in 6days.
A left work at 3rd day, till 50% work is completed.
Rest 50%, will be completed by B in 5 days.
So total days to complete the work is 3 + 5 = 8 days.
Posted from my mobile device
Please check.
As both can complete the work in 6days.
A left work at 3rd day, till 50% work is completed.
Rest 50%, will be completed by B in 5 days.
So total days to complete the work is 3 + 5 = 8 days.
Posted from my mobile device
The answer should be 8 days, not 36/5 days.
A & B together: 1/15 + 1/10 = 5/30 = 1wall/6 days
A leaves 3 days before finishing the work = A leaves after 3 days of work, when 1/2 wall is completed.
B has to finish the other 1/2 of the wall, working at a rate of 1wall/10days. It will take him 5 days to finish the work.
3 days (A & B) + 5 days (B alone) = 8 days.
Edit: this approach is wrong because I assumed A works 3 days.
A & B together: 1/15 + 1/10 = 5/30 = 1wall/6 days
A leaves 3 days before finishing the work = A leaves after 3 days of work, when 1/2 wall is completed.
B has to finish the other 1/2 of the wall, working at a rate of 1wall/10days. It will take him 5 days to finish the work.
3 days (A & B) + 5 days (B alone) = 8 days.
Edit: this approach is wrong because I assumed A works 3 days.
