Working at the same rate, 6 men can do 3/5 of a job in 20 minutes. At this rate, how many minutes would it take one man to do 1/4 of the job?
A. 30 minutes
B. 40 minutes
C. 50 minutes
D. 60 minutes
E. 70 minutes
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Working at the same rate, 6 men can do 3/5 of a job...
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6 men can do 3/5 of a job in 20 minutesPoisson wrote:Working at the same rate, 6 men can do 3/5 of a job in 20 minutes. At this rate, how many minutes would it take one man to do 1/4 of the job?
A. 30 minutes
B. 40 minutes
C. 50 minutes
D. 60 minutes
E. 70 minutes
So, 1 MAN can do 3/30 of a job in 20 minutes [divided 6 men by 6, and divided 3/5 by 6]
In other words, 1 MAN can do 1/10 of a job in 20 minutes
This means that, 1 MAN can do 2/10 of a job in 40 minutes
And 1 MAN can do 3/10 of a job in 60 minutes
Since 1/4 lies BETWEEN 2/20 and 3/10, we can conclude that it takes more than 40 minutes and less then 60 minutes to complete 1/4 of the job.
Answer: C
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Brent
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We can use the following formula:Poisson wrote:Working at the same rate, 6 men can do 3/5 of a job in 20 minutes. At this rate, how many minutes would it take one man to do 1/4 of the job?
A. 30 minutes
B. 40 minutes
C. 50 minutes
D. 60 minutes
E. 70 minutes
(number of workers)(number of minutes)/output = (number of workers)(number of minutes)/output
Let the job = the product of the two denominators = 5*4 = 20 units.
To produce 3/5 of the 20 units -- in other words, 12 units -- 6 men take 20 minutes.
We want to determine how many minutes are required for 1 worker to produce 1/4 of the 20 units -- in other words, 5 units.
Plugging these values into the formula above, we get:
(6*20)/12 = (1*x)/5
Solving the resulting equation, we get:
x = 50.
The correct answer is C.
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Hi Poisson,
In these types of questions, it often helps to simplify the given information one 'step' at a time.
Here, we're told that 6 men can do 3/5 of a job in 20 minutes. We rewrite the fraction as 6/10...
6 men do 6/10 of a job in 20 minutes. It's important to note that each man works for 20 minutes, so the work that is done in those 20 minutes is divided by the 6 men...
1 man does 1/10 of a job in 20 minutes
Now we can 'work up' to the full job...
1 man does 1/1 of a job in 20(10) = 200 minutes.
The questions asks how long it would take one man to do 1/4 of the job. Since the full job would take 1 man 200 minutes, 1/4 of the job would take (1/4)(200) = 50 minutes.
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
In these types of questions, it often helps to simplify the given information one 'step' at a time.
Here, we're told that 6 men can do 3/5 of a job in 20 minutes. We rewrite the fraction as 6/10...
6 men do 6/10 of a job in 20 minutes. It's important to note that each man works for 20 minutes, so the work that is done in those 20 minutes is divided by the 6 men...
1 man does 1/10 of a job in 20 minutes
Now we can 'work up' to the full job...
1 man does 1/1 of a job in 20(10) = 200 minutes.
The questions asks how long it would take one man to do 1/4 of the job. Since the full job would take 1 man 200 minutes, 1/4 of the job would take (1/4)(200) = 50 minutes.
Final Answer: C
GMAT assassins aren't born, they're made,
Rich
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DavidG@VeritasPrep
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A little old-fashioned algebra and our trusty formula R*T = W will do.Poisson wrote:Working at the same rate, 6 men can do 3/5 of a job in 20 minutes. At this rate, how many minutes would it take one man to do 1/4 of the job?
A. 30 minutes
B. 40 minutes
C. 50 minutes
D. 60 minutes
E. 70 minutes
The rate for one man: r; The rate for 6 men: 6r
Time: 20 minutes or 1/3 of an hour
Work: 3/5 of a job
6r * (1/3) = 3/5; r = 3/10
We know r = 3/10
We want 't,' when w = 1/4
(3/10) * t = 1/4; t = 10/12 = 5/6; 5/6 of an hour = 50 minutes. Answer is C
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We are given that 6 men can do 3/5 of a job in 20 minutes. Since rate = work/time, the rate of the 6 men is:Poisson wrote:Working at the same rate, 6 men can do 3/5 of a job in 20 minutes. At this rate, how many minutes would it take one man to do 1/4 of the job?
A. 30 minutes
B. 40 minutes
C. 50 minutes
D. 60 minutes
E. 70 minutes
(3/5)/20 = (3/5) x (1/20) = 3/100
We need to determine the number of minutes for 1 man to complete 1/4 of the job.
Since the rate of 6 men is 3/100, we divide that rate to get the rate for 1 man:
(3/100)/6 = (3/100) x (1/6) = 1/200
Finally, we can determine how long it would take 1 man to complete 1/4 of the job.
time = work/rate
time = (1/4)/(1/200) = (1/4) x (200/1) = 50 minutes
Answer: C
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Yemunn Soe
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Working @ same rate,
Together they will take 3/5(60%) of the work to be done in 20) minutes.
Each man will take 3/5(60%) of the work to be done in 120(6x20) minutes.
(Same work load/done but it will take more time for each)
Together 60% in 20 min
Together 6% in 2 min
Together 3% in 1 min
Together 1% in ...
Together (1/4) or 25% in 25 min
Each 60% in 120(6x20) min
Each 6% in 12 min
Each 3% in 6 min
Each 1% in 2 min
Each 25% in 50 min
The concept is get 1% of together work done and than each man work done.
The correct answer is 50 minutes
Together they will take 3/5(60%) of the work to be done in 20) minutes.
Each man will take 3/5(60%) of the work to be done in 120(6x20) minutes.
(Same work load/done but it will take more time for each)
Together 60% in 20 min
Together 6% in 2 min
Together 3% in 1 min
Together 1% in ...
Together (1/4) or 25% in 25 min
Each 60% in 120(6x20) min
Each 6% in 12 min
Each 3% in 6 min
Each 1% in 2 min
Each 25% in 50 min
The concept is get 1% of together work done and than each man work done.
The correct answer is 50 minutes
