CR : Companies O and P each have the same number of employee

This topic has expert replies
User avatar
Senior | Next Rank: 100 Posts
Posts: 89
Joined: Thu Sep 03, 2009 5:06 am
Thanked: 14 times
Followed by:1 members
GMAT Score:770
Companies O and P each have the same number of employees who work the same number of hours per week. According to records maintained by each company, the employees of Company O had fewer job-related accidents last year than did the employees of Company P. Therefore, employees of Company O are less likely to have job-related accidents than are employees of Company P.

Which of the following, if true, would most weaken the conclusion above?

(A) The employees of Company P lost more time at work due to job-related accidents than did the employees of Company O.
(B) Company P considered more types of accidents to be job-related than did Company O.
(C) The employees of Company P were sick more often than were the employees of Company O.
(D) Several employees of Company O each had more than one job-related accident.
(E) The majority of job-related accidents at Company O involved a single machine.

OA after discussion..

Senior | Next Rank: 100 Posts
Posts: 36
Joined: Mon Apr 12, 2010 4:59 am

by amitu » Thu Oct 21, 2010 9:11 am
B

after elimination two choices are left B and D .

since its a comparison , it should be about employees of both the company . D eliminated .

User avatar
Senior | Next Rank: 100 Posts
Posts: 89
Joined: Thu Sep 03, 2009 5:06 am
Thanked: 14 times
Followed by:1 members
GMAT Score:770

by prepgmat09 » Thu Oct 21, 2010 10:36 am
The conclusion is:
Employees of Company O are less likely to have job-related accidents than are employees of Company P.

B says: Company P considered more types of accidents to be job-related than did Company O.

Now let us take some concrete numbers.

Let there be 100 types of accidents at company P conidered job-related.
Let there be 10 types of accidents at company O conidered job-related.
Let there be a total of 1000 types of accident types.

The probability of an accident being a job-related accident in company P = 100/1000 = 0.1
The probability of an accident being a job-related accident in company O = 10/1000 = 0.01

So, doesn't B strengthen the conclusion that employees of Company O are less likely to have job-related accidents than are employees of Company P? Any explanations?

User avatar
Senior | Next Rank: 100 Posts
Posts: 89
Joined: Thu Sep 03, 2009 5:06 am
Thanked: 14 times
Followed by:1 members
GMAT Score:770

by prepgmat09 » Fri Oct 22, 2010 2:06 am
prepgmat09 wrote:The conclusion is:
Employees of Company O are less likely to have job-related accidents than are employees of Company P.

B says: Company P considered more types of accidents to be job-related than did Company O.

Now let us take some concrete numbers.

Let there be 100 types of accidents at company P conidered job-related.
Let there be 10 types of accidents at company O conidered job-related.
Let there be a total of 1000 types of accident types.

The probability of an accident being a job-related accident in company P = 100/1000 = 0.1
The probability of an accident being a job-related accident in company O = 10/1000 = 0.01

So, doesn't B strengthen the conclusion that employees of Company O are less likely to have job-related accidents than are employees of Company P? Any explanations?
Anyone who could help?

Senior | Next Rank: 100 Posts
Posts: 79
Joined: Mon Sep 15, 2008 5:54 pm
Thanked: 3 times

by DarkKnight » Sun Oct 24, 2010 5:50 pm
IMO its B.

If company P considers more types of accidents to be job related than company D, its clear that statement "the employees of Company O had fewer job-related accidents last year than did the employees of Company P" is not accurate. It just could be the case that several accidents that were counted as job related at company P were not accounted for at company O and hence does not portray an accurate picture of accidents at company O. Hence conclusion weakens.

Newbie | Next Rank: 10 Posts
Posts: 7
Joined: Tue Aug 16, 2011 9:49 am
Thanked: 1 times

by finalbattle » Tue Aug 23, 2011 10:40 am
can anyone explain this one????

User avatar
Master | Next Rank: 500 Posts
Posts: 154
Joined: Thu Aug 26, 2010 9:32 am
Location: Chicago,IL
Thanked: 46 times
Followed by:19 members
GMAT Score:760

by rkanthilal » Tue Aug 23, 2011 6:43 pm
This is a tricky one... I'll go with D but I'm not 100% positive...

P1: Companies O and P each have the same number of employees who work the same number of hours per week.
P2: According to records maintained by each company, the employees of Company O had fewer job-related accidents last year than did the employees of Company P.
C1: Employees of Company O are less likely to have job-related accidents than are employees of Company P.


The premises state that Companies O and P are equivalent in terms of number of employees and number of hours per week worked. Further, the premises state that the employees of Company O had fewer job-related accidents last year than did the employees of Company P. This is in aggregate. In other words, the total number of job-related accidents was less in Company O than in Company P.

The conclusion is that "Employees of Company O are less likely to have job-related accidents than are employees of Company P". In my opinion, since this statement doesn't include the words "on average", it is referring to the employees as individuals. Therefore, for the conclusion to be literally true, every employee of Company O would need to have a lower probability of having a job-related accident than the employee of Company P who has the lowest probability of having a job-related accident. In other words, if even one employee of Company O is more likely to have a job-related accident than any employee in Company P, then the statement that "employees of Company O are less likely to have job-related accidents than are employees of Company P" is no longer true.

Question Stem: Which of the following, if true, would most weaken the conclusion above?

We need an answer that shows that it is possible for an employee of Company O to be more likely to have a job-related accident than an employee of Company P.

(A) "The employees of Company P lost more time at work due to job-related accidents than did the employees of Company O." INCORRECT. This answer does not affect the conclusion in any way. It does not give us reason to believe that an employee of Company O may be more likely to have a job-related accident than an employee of Company P.

(B) "Company P considered more types of accidents to be job-related than did Company O." INCORRECT. This answer choice implies that the reason Company P had more job-related accidents is because the company has a broader definition of what constitutes a job-related accident than Company O does. This may lead you to believe that the number of job-related accidents in Company P is overstated. It is tempting to think that if we apply Company O's stricter definition of a job-related accident to Company P, the number of job-related accidents in Company P will decrease and the conclusion that employees of Company O are less likely to have a job-related accident would be weakened.

I don't believe we can do this. Nowhere in the argument does it state that Company O and Company P are in the same business and that the employees are performing identical jobs. It may be that Company P is in a much more dangerous business than Company O. In this case, it would justifiable for Company P to consider more types of accidents to be job-related than Company O. Applying Company O's definition of what constitutes a job-related accident to Company P would not be warranted in this situation.

Furthermore, this answer choice does not compare the likelihood of job-related accidents at the individual employee level. This is where I believe the conclusion is open to attack, as described above.

(C) "The employees of Company P were sick more often than were the employees of Company O." INCORRECT. The health of the employees is irrelevant to this argument. The premises state that each company has the same number of workers who work the same number of hours. This answer choice implies that employees of Company P actually worked less than employees of Company O. However, all this answer states is that employees of Company P were sick. It does not state that they missed work.

Regardless, similar to the other incorrect answers, this answer choice does not compare the likelihood of job-related accidents at the individual employee level.

(D) "Several employees of Company O each had more than one job-related accident." CORRECT. This answer choice addresses the employees of Company O at an individual level instead of in aggregate. If several employees of Company O each had more than one job-related accident, then it is possible that there are specific employees in Company O that are more likely to have a job-related accident than employees in Company P.

For example, imagine that several employees of Company O each had more than one job-related accident and one employee in Company P had no job-related accidents. Company P may still have in total more job-related accidents than Company O, but there would exist specific employees in Company O that are more likely to have a job-related accident than that one employee in Company P who had zero job-related accidents. This would weaken the conclusion that "Employees of Company O are less likely to have job-related accidents than are employees of Company P".

This answer doesn't prove that there are employees in Company O that are more likely to have an accident than employees in Company P. All this answer choice does is open the possibility that there could be an employee at Company O that is more likely to have an accident than an employee in Company P. In my opinion, this is good enough to weaken the conclusion.

(E) "The majority of job-related accidents at Company O involved a single machine." INCORRECT. We need an answer that shows that it is possible for an employee of Company O to be more likely to have a job-related accident than an employee of Company P. How the job-related accidents happened is irrelevant to the argument.

Legendary Member
Posts: 581
Joined: Sun Apr 03, 2011 7:53 am
Thanked: 52 times
Followed by:5 members

by killer1387 » Fri Aug 26, 2011 1:26 am
OA???

User avatar
Master | Next Rank: 500 Posts
Posts: 496
Joined: Tue Jun 07, 2011 5:34 am
Thanked: 38 times
Followed by:1 members

by sl750 » Sat Aug 27, 2011 6:33 am
B. It tells us that Company O may not consider all types of accidents worthy enough of being recorded

Legendary Member
Posts: 2789
Joined: Tue Jul 26, 2011 12:19 am
Location: Chennai, India
Thanked: 206 times
Followed by:43 members
GMAT Score:640

by GmatKiss » Sat Aug 27, 2011 9:14 am
B it is!!

User avatar
Master | Next Rank: 500 Posts
Posts: 154
Joined: Thu Aug 26, 2010 9:32 am
Location: Chicago,IL
Thanked: 46 times
Followed by:19 members
GMAT Score:760

by rkanthilal » Sat Aug 27, 2011 12:49 pm
There's no OA here but based on the postings by prepgmat09 the OA is most likely B.

If I got this question on the actual test I would pick D every time based on my reasons above. I would love to hear an expert's analysis of this question...

Master | Next Rank: 500 Posts
Posts: 125
Joined: Fri Aug 12, 2011 6:11 pm
Thanked: 8 times

by crick » Sun Aug 28, 2011 12:00 am
I will go with B here.

Premise1: No of employees at O = No of employees at P.
Premise2: Last year : No of job related accidents at O < No of job related accidents at P
Conclusion: Employees at Company O are less likely to have job-related accidents than employees at Company P

In effect this means,

Accidents per employee at O < Accident per employee at P.
B attacks this reasoning by indicating that the definition of job-related accidents is different at both O and P, hence Premise2 cannot lead to Conclusion.

D is incorrect because it does not say anything about the Total number of accidents.

User avatar
Master | Next Rank: 500 Posts
Posts: 154
Joined: Thu Aug 26, 2010 9:32 am
Location: Chicago,IL
Thanked: 46 times
Followed by:19 members
GMAT Score:760

by rkanthilal » Sun Aug 28, 2011 8:25 am
Hi crick,
Premise1: No of employees at O = No of employees at P.
Premise2: Last year : No of job related accidents at O < No of job related accidents at P
Conclusion: Employees at Company O are less likely to have job-related accidents than employees at Company P

In effect this means,

Accidents per employee at O < Accident per employee at P.
"Accidents per employee at O < Accident per employee at P" is a comparison of averages. This is equivalent to "ON AVERAGE, employees at Company O are less likely to have job-related accidents than employees at Company P". This is not the same as the conclusion.

The conclusion is "Employees at Company O are less likely to have job-related accidents than employees at Company P". This literally means that every employee at Company O is less likely to have a job-related accident than the employee at Company P that is the least likely to have a job-related accident. In other words, if at least one employee at Company O is more accident prone than at least one employee at Company P, then the conclusion "employees at Company O are less likely to have job-related accidents than employees at Company P" is no longer valid.
B attacks this reasoning by indicating that the definition of job-related accidents is different at both O and P, hence Premise2 cannot lead to Conclusion.
In my opinion, the difference in the definition of "job-related accident" between the two companies is irrelevant to this argument. For example, imagine that Company P is a coal miner and Company O is a florist. The coal mining business is inherently more accident prone than the floral business. Employees in a coal mine have much more opportunity to have a job-related accident than employees in a flower shop. The coal miner will have a much broader definition of "job-related accident" than the florist and this is completely justifiable based on the nature of the respective businesses.

The only way the definition of "job-related accident" can be considered is if we know that Company O and P are in the same business. If we know this, then we can insist that the definitions be the same for comparative purposes. Since the passage does not state that the companies are in the same business, the definition of "job-related accident" is no longer relevant.

For example, imagine the conclusion was the following: "On average, employees of a florist are less likely to have job-related accidents than are employees of a coal miner". Does the fact that the coal mining company has a broader definition of "job-related accident" take anything away from this conclusion? NO. If anything it is supportive of the conclusion. The fact that the coal miner is in a more dangerous business with a broader range of possible job-related accidents makes an employee of the coal miner more likely to have an accident than the employee of a florist (all else being equal).
D is incorrect because it does not say anything about the Total number of accidents.
I like D specifically because it does not say anything about the Total number of accidents. It addresses accidents at the employee level which is what I believe the conclusion does.

As stated above, for the conclusion to be literally true every employee of Company O would need to have a lower probability of having a job-related accident than the employee of Company P who has the lowest probability of having a job-related accident.

Per the premises, we know that "Company O had fewer job-related accidents last year than did the employees of Company P". This premise leaves open the possibility that Company O had zero accidents and Company P had more than zero accidents. In this case, for the conclusion to be true, every employee of Company P would need to have at least one accident. An answer choice that shows that at least one employee of Company P had zero accidents would weaken the conclusion because it would imply that that employee of Company P is equally likely to have an accident as employees of Company O.

Answer choice (D) weakens the conclusion in a slightly different way. Answer (D) states, "Several employees of Company O each had more than one job-related accident". If we know that there were some job-related accidents by the employees of Company O then that opens up the possibility that an employee of Company P could be less likely to have an accident than some employees of Company O.

User avatar
Legendary Member
Posts: 540
Joined: Sat Dec 20, 2008 7:24 pm
Thanked: 37 times
Followed by:6 members

by navami » Mon Aug 29, 2011 7:40 am
gt to be B
This time no looking back!!!
Navami

User avatar
GMAT Instructor
Posts: 905
Joined: Sun Sep 12, 2010 1:38 am
Thanked: 378 times
Followed by:123 members
GMAT Score:760

by Geva@EconomistGMAT » Tue Aug 30, 2011 12:40 am
prepgmat09 wrote:Companies O and P each have the same number of employees who work the same number of hours per week. According to records maintained by each company, the employees of Company O had fewer job-related accidents last year than did the employees of Company P. Therefore, employees of Company O are less likely to have job-related accidents than are employees of Company P.

Which of the following, if true, would most weaken the conclusion above?

(A) The employees of Company P lost more time at work due to job-related accidents than did the employees of Company O.
(B) Company P considered more types of accidents to be job-related than did Company O.
(C) The employees of Company P were sick more often than were the employees of Company O.
(D) Several employees of Company O each had more than one job-related accident.
(E) The majority of job-related accidents at Company O involved a single machine.

OA after discussion..
At first glance, the argument seems solid. Same number of employees, same number of hours, yet records show that O has fewer job-related accidents than P. Clearly, O is the safer place - they have fewer accident reports, right?

Think - how could we weaken this argument? In order to do that, we need to show that O and P have the same actual number of accidents (=same probability of job-related accident, assuming same number of employees) DESPITE having reported fewer accidents in O. The only way to do this is if there's something wrong with the REPORTS.

B explains that perfectly: If B is true, then it is possible that O has the same number of accidents overall, and is not safer for employees - they just don't consider them job-related, so they don't appear in the reports.

D is irrelevant, since the reports discuss overall number of accidents, not number of employees hurt by accidents. Therefore, we have to assume that the accidents that happened to the same employee would still be counted separately in the reports. If anything, D strengthens the notion that you O is indeed the safer place - as long as you're not the one operating the automatic wood-chipper, for instance.
Geva
Senior Instructor
Master GMAT
1-888-780-GMAT
https://www.mastergmat.com