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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A)5
(B)2
(C)8
(D)4
(E)6

Assume the order to be welding 45 rods...

Each welder works at 1 rod per day

On first day 15 rods are completed.

So now 30 rods have to be completed by 6 workers...

So, the answer is 30/6 = 5 days
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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A)5
(B)2
(C)8
(D)4
(E)6

Similar question to practice: 6-workers-should-finish-a-job-in-8-days-after-3-days-came-153377.html

Hope it helps.
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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A)5
(B)2
(C)8
(D)4
(E)6

1. We need to find out the time taken by 6 workers after day 1.
2. total no.of wokers * total time taken = time taken by 1 worker
3. Time taken by 1 worker = 15*3 = 45 days
4. But on day 1 fifteen workers had already worked finishing 1/3 of the job. So 6 workers have to finish only 2/3 of the job.
5. Total time taken by 6 workers can be got from formula used at (2). i.e., 6* total time taken = 45. Total time taken by 6 workers to finish the complete job is 45/ 6 = 7.5 days.
6. Time taken by 6 workers to finish 2/3 of the job is 2/3 * 7.5 = 5 days.

The answer is choice A
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Hello Brunel is this right approach

Rate of 15 workers = 1/3 job / day
Rate of 1 worker = 1/45 job / day

as 15 workers work for single day and 6 workers work for more days (x)

So now equation becomes

1/3 + 6/45(x-3) = 1
Solving this we get x=8

So 6 workers need x-3more days ie = 5days
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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A) 5
(B) 2
(C) 8
(D) 4
(E) 6


sol:

15 welders rate of job = 1/3

W= 1 (1/3) = 1/3

Remaining Job = 1-(1/3) = 2/3

Job---days---number of welders

2/3------2----------15
2/3------X ---------15-9 = 6


X= 2* (15/6) =5 days
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Man Days = Work

15 people * 3 days = 45 units of work

15 people * 1 day = 15 units

Work left = 45 -15 = 30 units

People left to work = 15-9= 6

6 people * x days = 30

x=5
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Let rate of each worker be \(\frac{1}{x}\)
For 15 workers the rate is \(\frac{15}{x}\)

\(\frac{15}{x}\) = \(\frac{1}{3}\)
Hence rate of each worker is \(\frac{1}{45}\)

After day 1, \(\frac{1}{3}\) of the work will be complete, hence \(\frac{2}{3}\) of the work remains
The number of workers has now dropped from 15 to 6 (Since 9 workers left)
Rate of 6 workers = \(\frac{6}{x}\) = 6 * \(\frac{1}{45}\) = \(\frac{2}{15}\)

W= \(\frac{2}{3}\) ; R = \(\frac{2}{15}\); T = \(\frac{W}{R}\)
T = 5

Answer is A
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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A) 5
(B) 2
(C) 8
(D) 4
(E) 6


15x1/1/3 = 6xt/2/3

solving this we get, t= 5

hope this helps ....
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Total work = 15*3 = 45 man days
1 st day = 15*1 = 15 man days

Rem work = 45-15 = 30 man days

This can be completetd in 30/6 = 5 days
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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A) 5
(B) 2
(C) 8
(D) 4
(E) 6

We are given that the rate of 15 welders is 1/3. Thus, after 1 day, 2/3 of the job is left to complete for 6 welders. If we let x = the rate of 6 welders, we can create the proportion to determine their rate:

15/(1/3) = 6/x

15x = 2

x = 2/15

Thus, the 6 welders will complete the job in (2/3)/(2/15) = 30/6 = 5 days.

Answer: A
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gmatquant25
15 welders work at a constant rate they complete an order in 3 days. If after the first day, 9 welders start to work on the other project, how many more days the remaining welders will need to complete the rest of the order?

(A) 5
(B) 2
(C) 8
(D) 4
(E) 6

15 Welders were supposed to do the job in 3 days but 9 of them left after one day. If none let left then whey will work 2 more days.

So 15 welders will do job in 2 days (because they already worked one day)
6 welders will need (15 x 2)/6= 5 Ans a.
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Another way around as taught by this forum experts:

15 workers can complete in 3 days = 45 man days work is there

now on the first day all 15 worked, so 15 manday work is finished.

now 30 man day work is left with and only 6 workers are available. So the six workers will complete the said 30 manday work in 5 days.
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