Work Rate DS Problem

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Work Rate DS Problem

by Bens4vcobra » Mon Jun 20, 2011 4:14 pm
To fill an order on schedule, a manufacturer had to produce 1000 tools per day for N days, what is the value of N?

1) Because of production problems, the manufacturer only produced 600 tools for the first 5 days
2) Because of production problems, the manufacturer had to produce 1500 tools per day for each of the last 4 days to meet the schedule
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by ChrisK » Mon Jun 20, 2011 10:01 pm
Hi, IMHO:

This is a work rate problem. Upfront, we have:

Rate = 1000/day
Time = N days
Job = 1000N

Therefore, in order to get the value of N, we need to know the value of the job.

Statement #1 - This tells us that the manufacturer has produced only 600 tools over the first five days, but tells us nothing about how many more days the manufacturer will be producing tools.

State#2 - This tells us that over the last 4 days, the manufacturer produced 1500 tools/day (6,000 total) but does not tell us how many days of production problems the manufacturer had.

Neither of the statements individually tell us enough to answer the question.

Let's look at them together.

Statement #1 tells us that we have 600 tools after 5 days. Statement #2 tells us that the job is done once 6,000 more tools are produced. Taken together, this tells us that the job is for 6,600 tools total.

Going back to the original question;
Job = rate X time
6,600 = 1,000 X N
N = 6.6 days

Therefore, the answer is [spoiler]'C'[/spoiler]

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by Frankenstein » Mon Jun 20, 2011 10:04 pm
Bens4vcobra wrote: 1) Because of production problems, the manufacturer only produced 600 tools for the first 5 days
Hi,
Can you check statement(1) again. Is it 600tools per day for the first 5 days? Please check for errors while posting the question.
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by Geva@EconomistGMAT » Mon Jun 20, 2011 10:13 pm
Bens4vcobra wrote:To fill an order on schedule, a manufacturer had to produce 1000 tools per day for N days, what is the value of N?

1) Because of production problems, the manufacturer only produced 600 tools for the first 5 days
2) Because of production problems, the manufacturer had to produce 1500 tools per day for each of the last 4 days to meet the schedule
Meh. Obviously neither of the statements is sufficient on its own. I guess they want you to think that the combination is sufficient (600+ 4*1500 = 6600, so N=7). The problem is that the statements are phrased as "the first 5 days" and "the last 4 days" - not "the first 5 days" and the "NEXT four days". Between the first 5 and the last 4, you can sneak in a whole YEAR of working at exactly 1000 tools per day - there's no requirement that the last 4 come immediately after the first 5. Answer should be E.

EDIT: 600 for the first 5 days altogether, not 600 per day. Doesn't matter.
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by worldpeace93 » Mon Jun 20, 2011 10:34 pm
Answer should be E,as both statements combined or alone don't metion the total no of working days.

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by bubbliiiiiiii » Tue Jun 21, 2011 12:28 am
Thanks Geva@MasterGMAT sir for your insights. :)

Even I picked C and then later understood why E and not C.
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by ChrisK » Tue Jun 21, 2011 2:53 am
Thanks guys, that was a critical oversight on my part.

Sorry Bens.

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by Bens4vcobra » Tue Jun 21, 2011 6:29 am
ChrisK wrote:Thanks guys, that was a critical oversight on my part.

Sorry Bens.

Chris
No problem I did exactly what you did! I assumed the total days were 9 and that the order was filled on schedule. I fell for the trap.
Last edited by Bens4vcobra on Tue Jun 21, 2011 6:31 am, edited 1 time in total.
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by Bens4vcobra » Tue Jun 21, 2011 6:30 am
Frankenstein wrote:
Bens4vcobra wrote: 1) Because of production problems, the manufacturer only produced 600 tools for the first 5 days
Hi,
Can you check statement(1) again. Is it 600tools per day for the first 5 days? Please check for errors while posting the question.
Pretty sure I typed the question correctly.
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by Sanjay2706 » Mon Jun 27, 2011 2:04 am
Answer is E, as it is not clear whether there were only 9 days.
The first 5 days and last 4 days does not mean that there were only 9 days.
Tricky one.