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If 6 men can do a piece of work in 30 days of 9 hours each,
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15 Jan 2014, 22:50
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Question Stats:
82% (02:16) correct 18% (02:18) wrong based on 271 sessions
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If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?
A. 61 B. 64 C. 84 D. 81 E. 94
Please help explains using rates formulae as I could not get the answer. Thanks
Re: If 6 men can do a piece of work in 30 days of 9 hours each,
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21 Jul 2015, 21:25
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smartyman wrote:
If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?
A. 61 B. 64 C. 84 D. 81 E. 94
Please help explains using rates formulae as I could not get the answer. Thanks
i.e. \(\frac{(M_1 * T_1)}{W_1} = \frac{(M_2 * T_2)}{W_2}\)
i.e. \(\frac{[6 * (30*9)]}{W} = \frac{[M_2 * (25*8)]}{(10*W)}\)
i.e. \(M_2 = 81\)
Answer: option D
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Re: If 6 men can do a piece of work in 30 days of 9 hours each,
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16 Jan 2014, 01:07
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smartyman wrote:
If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours? A. 61 B. 64 C. 84 D. 81 E. 94
Please help explains using rates formulae as I could not get the answer. Thanks
Amount of work done by 6 men working 30 days working 9 hrs each = 30 * 9 * 6 Let the number of people required for the 2nd case = X
Then X * 25 * 8 = 30 * 9 * 6 * 10 = > X = 81 - Option D)
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Re: If 6 men can do a piece of work in 30 days of 9 hours each,
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16 Jan 2014, 20:53
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smartyman wrote:
If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?
A. 61 B. 64 C. 84 D. 81 E. 94
Please help explains using rates formulae as I could not get the answer. Thanks
Or you can do it using joint variation:
Number of men required = 6 * (30/25) * (9/8) * 10 = 81
Re: If 6 men can do a piece of work in 30 days of 9 hours each,
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18 Jul 2014, 03:21
Can someone please explain any other method, preferably the w=rt method. Work rate problems always seem so simple but I always go wrong or am stuck. I was not able to grasp it even after going through the two approaches. Thank you.
If 6 men can do a piece of work in 30 days of 9 hours each,
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18 Jul 2014, 03:38
In this type of problems, converting for unit values will make it easy to solve.
Take a look at the first sentence. We can say, to do the work in 1 day of 9 hours each will take 6*30 men. To do the work in 25 days will take (6*30) /25 men Similarly adding the info, that to do the work in a day of 8 hours instead of 9 hours each will take (6 *30*9)/ (25*8) men To do 10 times the amount of work will take 10 * (6*30*9) / (25*8) = 81 men
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Re: If 6 men can do a piece of work in 30 days of 9 hours each,
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25 Sep 2016, 12:06
If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?
A. 61 B. 64 C. 84 D. 81 E. 94
6*30*9=1620 total man hours to do work let m=number of men needed m*25*8*1/1620=10 m=81 men D.
If 6 men can do a piece of work in 30 days of 9 hours each,
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30 Nov 2017, 12:56
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smartyman wrote:
If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?
A. 61 B. 64 C. 84 D. 81 E. 94
Please help explains using rates formulae as I could not get the answer. Thanks
One version of the rate formula approach . . . Use standard W = RT formula, but add (# of workers or machines) to R*T, thus: W = #*R*T
Work = (# of workers) * individual rate * time
Scenario 1
Get individual rate from first scenario, where t = (30 * 9hrs = 270 hrs)
Work = # * r * t
1 = 6 * ?? * 270
1 = r * 1620
r = \(\frac{1}{1620}\)
Scenario 2
At that rate, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours? t = (25 * 8 hrs = 200 hrs)
Work = # * r * t
10 = ?? * \(\frac{1}{1620}\) * 200
10 = # * \(\frac{200}{1620}\)
# of workers = \(\frac{10}{(\frac{200}{1620})} =\)
# of workers =\((10 * \frac{1620}{200})=(\frac{1620}{20})=\frac{162}{2}= 81\)
Answer D
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Re: If 6 men can do a piece of work in 30 days of 9 hours each,
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01 Dec 2017, 06:49
smartyman wrote:
If 6 men can do a piece of work in 30 days of 9 hours each, how many men will it take to do 10 times the amount of work if they work for 25 days of 8 hours?
A. 61 B. 64 C. 84 D. 81 E. 94
The hourly rate of the 6 men is 1/(30 x 9) = 1/270. If we let x = the number of men needed to do 10 times the work when they work for 25 days of 8 hours, then the hourly rate of these x men must be 10/(25 x 8) = 10/200 = 1/20. We can create the following proportion and solve for x:
6/(1/270) = x/(1/20)
1620 = 20x
x = 1620/20 = 81
Answer: D
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