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the conclusion "employees at Company O are less likely to have job-related accidents than employees at Company P" is no longer valid.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.
