- A. 5/6
B. 1
C. 6/5
D. 5/6
E. 5
Work
- sivaelectric
- Master | Next Rank: 500 Posts
- Posts: 439
- Joined: Sat Aug 09, 2008 8:32 am
- Location: India
- Thanked: 34 times
- Followed by:28 members
It takes James 2 hours to mow a lawn and Fred 3 hours to mow the same lawn. How many hours would it take both men working simultaneously at their respective constant rates, to mow the lane?
If I am wrong correct me , If my post helped let me know by clicking the Thanks button .
Chitra Sivasankar Arunagiri
Chitra Sivasankar Arunagiri
-
- Master | Next Rank: 500 Posts
- Posts: 401
- Joined: Tue May 24, 2011 1:14 am
- Thanked: 37 times
- Followed by:5 members
James rate 1/2
Fred rate 1/3
James + Fred 1/2 + 1/3 = 5/6
Time required by both = 1/5/6 = 6/5
:p
Fred rate 1/3
James + Fred 1/2 + 1/3 = 5/6
Time required by both = 1/5/6 = 6/5
:p
-
- Senior | Next Rank: 100 Posts
- Posts: 32
- Joined: Sat Nov 27, 2010 9:21 am
- GMAT Score:560
- smackmartine
- Legendary Member
- Posts: 516
- Joined: Fri Jul 31, 2009 3:22 pm
- Thanked: 112 times
- Followed by:13 members
IMO C
Best way to tackle work related problems is to use basic formula RT=D , where R= rate, T= time and D = work
Rj(2) = 1
Rf(3) = 1
When James and Fred work together, their respective rate gets added
So, (Rj+Rf)* T =1
(1/2 + 1/3)* T = 1
(5/6)* T =1
T = 6/5
Best way to tackle work related problems is to use basic formula RT=D , where R= rate, T= time and D = work
Rj(2) = 1
Rf(3) = 1
When James and Fred work together, their respective rate gets added
So, (Rj+Rf)* T =1
(1/2 + 1/3)* T = 1
(5/6)* T =1
T = 6/5
- jainnikhil02
- Master | Next Rank: 500 Posts
- Posts: 123
- Joined: Tue May 31, 2011 12:26 am
- Location: Hyderabad
- Thanked: 5 times
- Followed by:1 members
Its the normal logic we use in the work related problem.... answer is 6/5[/url]
Nikhil K Jain
____________________
"Life is all about timing" Don't waste your and others time.
____________________
"Life is all about timing" Don't waste your and others time.
-
- Legendary Member
- Posts: 1085
- Joined: Fri Apr 15, 2011 2:33 pm
- Thanked: 158 times
- Followed by:21 members
i would answer c and 6/5 if a word selected in the text would be replaced with the word 'together' likewise, speed of James 1/2 and speed of Fred 1/3; their combined speed 1/2 + 1/3 =5/6 and the time spend for a job is 1 : 5/6 or 6/5
BUT it says simultaneously, hence 5 and e
BUT it says simultaneously, hence 5 and e
sivaelectric wrote:It takes James 2 hours to mow a lawn and Fred 3 hours to mow the same lawn. How many hours would it take both men working simultaneously at their respective constant rates, to mow the lane?
- A. 5/6
B. 1
C. 6/5
D. 5/6
E. 5
Success doesn't come overnight!
- Stuart@KaplanGMAT
- GMAT Instructor
- Posts: 3225
- Joined: Tue Jan 08, 2008 2:40 pm
- Location: Toronto
- Thanked: 1710 times
- Followed by:614 members
- GMAT Score:800
Hi,sivaelectric wrote:It takes James 2 hours to mow a lawn and Fred 3 hours to mow the same lawn. How many hours would it take both men working simultaneously at their respective constant rates, to mow the lane?
- A. 5/6
B. 1
C. 6/5
D. 5/6
E. 5
there's a very simple formula to solve 2-worker problems:
Combined Time = (t1*t2)/(t1+t2)
So, we simply have:
CT = (2*3)/(2+3) = 6/5
That formula is derived from the more standard work formula:
1/(combined time) = 1/t1 + 1/t2+ 1/t3 + ...
in which t1, t2, t3 and so on are the times it takes individual workers to complete a job.
Stuart Kovinsky | Kaplan GMAT Faculty | Toronto
Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course
-
- Legendary Member
- Posts: 1448
- Joined: Tue May 17, 2011 9:55 am
- Location: India
- Thanked: 375 times
- Followed by:53 members
Hi,pemdas wrote:i would answer c and 6/5 if a word selected in the text would be replaced with the word 'together' likewise, speed of James 1/2 and speed of Fred 1/3; their combined speed 1/2 + 1/3 =5/6 and the time spend for a job is 1 : 5/6 or 6/5
BUT it says simultaneously, hence 5 and e
'simultaneously' means 'at the same time'. Why will it be '5'?
Cheers!
Things are not what they appear to be... nor are they otherwise
Things are not what they appear to be... nor are they otherwise
-
- Legendary Member
- Posts: 1085
- Joined: Fri Apr 15, 2011 2:33 pm
- Thanked: 158 times
- Followed by:21 members
If you and me work on the same project BUT we aren't told to work together - ONLY at the same time (simultaneously); it takes you 2 hours and me 3 hours. How long will it take both of us to work through the same job? I guess I will be spending 2 hours of my time and you need to spend 3 hours of your time. It should take us 5 hours to complete the same job, agree?
look options a and d are identical even
@seva, please reveal the source and OA
it must be mistake in this q. I tend to select c but the text is asking for e
1/(combined time) = combined speed (by allowing 1 as the whole or ONE job)
look options a and d are identical even
@seva, please reveal the source and OA
it must be mistake in this q. I tend to select c but the text is asking for e
I used exactly this approach above where 1/t1 + 1/t2+ 1/t3 + ... is combined speed andStuart Kovinsky wrote: 1/(combined time) = 1/t1 + 1/t2+ 1/t3 + ...
in which t1, t2, t3 and so on are the times it takes individual workers to complete a job.
1/(combined time) = combined speed (by allowing 1 as the whole or ONE job)
Success doesn't come overnight!
- edvhou812
- Master | Next Rank: 500 Posts
- Posts: 143
- Joined: Sat Nov 06, 2010 9:06 pm
- Thanked: 10 times
- Followed by:1 members
The answer to these is always the reciprocal of the sum of the fractions.sivaelectric wrote:It takes James 2 hours to mow a lawn and Fred 3 hours to mow the same lawn. How many hours would it take both men working simultaneously at their respective constant rates, to mow the lane?
- A. 5/6
B. 1
C. 6/5
D. 5/6
E. 5
-
- Legendary Member
- Posts: 1448
- Joined: Tue May 17, 2011 9:55 am
- Location: India
- Thanked: 375 times
- Followed by:53 members
Hi,pemdas wrote:If you and me work on the same project BUT we aren't told to work together - ONLY at the same time (simultaneously); it takes you 2 hours and me 3 hours. How long will it take both of us to work through the same job? I guess I will be spending 2 hours of my time and you need to spend 3 hours of your time. It should take us 5 hours to complete the same job, agree?
it must be mistake in this q. I tend to select c but the text is asking for e
I think your explanation is unnecessarily(unintentionally) misleading. The meaning of the question is working together. If both are working at the same time, why would it take 2 hours for one and 3 hours for the other. Let me try to explain this part. If it is taking 2 hours for one, that means you are assuming the other guy hasn't worked on that lawn for the 2 hours.Similarly, for the other. One more thing is if you are adding 2 hours and 3 hours, that means one has already done the work of mowing the lawn and then the second one is again doing the same after the first one has completed.
Even if the wording doesn't say working together, still 'working simultaneously' is closer in meaning to working together than 'one doing the work and then another doing the same work which has already been done'.
Cheers!
Things are not what they appear to be... nor are they otherwise
Things are not what they appear to be... nor are they otherwise
- cans
- Legendary Member
- Posts: 1309
- Joined: Mon Apr 04, 2011 5:34 am
- Location: India
- Thanked: 310 times
- Followed by:123 members
- GMAT Score:750
work=1
Thuse Rate james=1/2 and rate fred=1/3
total rate=5/6. work=1
time=6/5
IMO D
Thuse Rate james=1/2 and rate fred=1/3
total rate=5/6. work=1
time=6/5
IMO D
If my post helped you- let me know by pushing the thanks button
Contact me about long distance tutoring!
[email protected]
Cans!!
Contact me about long distance tutoring!
[email protected]
Cans!!
-
- Legendary Member
- Posts: 1085
- Joined: Fri Apr 15, 2011 2:33 pm
- Thanked: 158 times
- Followed by:21 members
@Frankenstein, it was said - i tend for c
i understand wording may be confusing, and it is
e was off-price for this question and i keep c as the final answer
basically we are done with the same answer choice, as per my earliest explanation
i understand wording may be confusing, and it is
e was off-price for this question and i keep c as the final answer
basically we are done with the same answer choice, as per my earliest explanation
Success doesn't come overnight!
-
- Junior | Next Rank: 30 Posts
- Posts: 13
- Joined: Tue May 17, 2011 9:27 am
- GMAT Score:620
sivaelectric wrote:It takes James 2 hours to mow a lawn and Fred 3 hours to mow the same lawn. How many hours would it take both men working simultaneously at their respective constant rates, to mow the lane?
- A. 5/6
B. 1
C. 6/5
D. 5/6
E. 5
John's Rate * time = work
John's Rate * 2 = 1
John's rate = 1/2
Similarly, Fred's rate is 1/3.
Their combined rate for one hour is:-
(1/2 + 1/3 ) * 1 = work
5/6 is the amount of work they can complete in one hour.
Total amount of work they need to complete is 1.
Therefore,
Rate * time = work
5/6 * time = 1
Solution: Time needed is 6/5
- GMATGuruNY
- GMAT Instructor
- Posts: 15539
- Joined: Tue May 25, 2010 12:04 pm
- Location: New York, NY
- Thanked: 13060 times
- Followed by:1906 members
- GMAT Score:790
Let job = 6 units.sivaelectric wrote:It takes James 2 hours to mow a lawn and Fred 3 hours to mow the same lawn. How many hours would it take both men working simultaneously at their respective constant rates, to mow the lane?
- A. 5/6
B. 1
C. 6/5
D. 5/6
E. 5
Rate for James = w/t = 6/2 = 3 units per hour.
Rate for Fred = w/t = 6/3 = 2 units per hour.
Combined rate for James and Fred = 3+2 = 5 units per hour.
Time for James and Fred to complete the job = w/r = 6/5 hours.
The correct answer is C.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.
As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.
For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3