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.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
N
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
(N/A)
Question Stats:
0% (00:00) correct
100%
(00:33)
wrong
based on 1
sessions
History
Date
Time
Result
Not Attempted Yet
If ‘A’ can complete a task in 3 hours and ‘B’ can complete the same task in 6 hours, how long will it take if both of them work together to complete the task?
Please explain the logic.
Thanks
Please explain the logic.
Thanks
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block below for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
30 Dec 2009, 03:06
Kudos
Bookmarks
first thing david
the problem never asked about the mean time , the problem is asking how much time it will if bth does the work together . there is a huge diff in bth the cases.
secondly there is a direct formula to handle such problem
if A takes x hrs and B takes y hrs to do a work independently then , combining they will
take x*y/(x+y) hrs
in this case----> 3*6/(3+6)=18/9=2
the problem never asked about the mean time , the problem is asking how much time it will if bth does the work together . there is a huge diff in bth the cases.
secondly there is a direct formula to handle such problem
if A takes x hrs and B takes y hrs to do a work independently then , combining they will
take x*y/(x+y) hrs
in this case----> 3*6/(3+6)=18/9=2
01 Jan 2010, 11:22
Kudos
Bookmarks
The best approach to these problems is to get the 1 hr work done by each participant.
To explain:
If ‘A’ can complete a task in 3 hours and ‘B’ can complete the same task in 6 hours, how long will it take if both of them work together to complete the task?
In 3 hrs, A can do = 1 Task (read as complete Task)
In 1 hr, A can do \(=\frac{1}{3}\) Task
Similarly
In 6 hrs, B can do = 1 Task
In 1 hr, B can do \(=\frac{1}{6}\) Task
Therefore the task done by both A and B in 1 hr \(=\frac{1}{3} + \frac{1}{6} = \frac{1}{2}\) Task
Now \(\frac{1}{2}\) Task is done by both A & B in = 1 hr
1 Task (read as complete Task) is done by both A & B in \(= 1 / \frac{1}{2}\) hrs = 2 hrs
Reason for this detail approach is that with this understanding you can solve questions involving more than 2 people and also with complex combinations....
Hope this helps!
Cheers!
JT
To explain:
If ‘A’ can complete a task in 3 hours and ‘B’ can complete the same task in 6 hours, how long will it take if both of them work together to complete the task?
In 3 hrs, A can do = 1 Task (read as complete Task)
In 1 hr, A can do \(=\frac{1}{3}\) Task
Similarly
In 6 hrs, B can do = 1 Task
In 1 hr, B can do \(=\frac{1}{6}\) Task
Therefore the task done by both A and B in 1 hr \(=\frac{1}{3} + \frac{1}{6} = \frac{1}{2}\) Task
Now \(\frac{1}{2}\) Task is done by both A & B in = 1 hr
1 Task (read as complete Task) is done by both A & B in \(= 1 / \frac{1}{2}\) hrs = 2 hrs
Reason for this detail approach is that with this understanding you can solve questions involving more than 2 people and also with complex combinations....
Hope this helps!
Cheers!
JT
Archived Topic
Hi there,
This topic has been closed and archived due to inactivity or violation of community quality standards. No more replies are possible here.
Where to now? Join ongoing discussions on thousands of quality questions in our Problem Solving (PS) Forum
Still interested in this question? Check out the "Best Topics" block above for a better discussion on this exact question, as well as several more related questions.
Thank you for understanding, and happy exploring!
