Q25 - At the company picnic, all

[eric.zeleznik]

I think i understand this question but I just want to be sure. Is the flaw basically that the argument doesn't account for the employees who might have participated in exactly 4 of the events?

[Shiggins]

I believe you are correct.
When I did this problem I looked at the language to pick my choice.
It discusses all, then some, and concludes with most. This is not always the best option but it helped me quickly get choice E.

Now to understand the argument I will use numbers:
Lets say there are 100 people who are at the company picnic.

Say 25 people participate in 4+ events, they are eligible for raffle

We then are told only a small portion are eligible.

The small portion eligible are the 25 who were in 4+ events

The author then concludes that most of the employees must have participated in fewer than 4.
I believe in categorical logic "most" means more than 50%

If more than 50%, lets say 60 people participated in fewer than 4 events, then that leaves 15 people who participated in exactly 4 events. Could it be that maybe 60 people actually did exactly 4 events. This is something the author has overlooked.

Choices:
A- The flaw here is assuming the 3rd and 4th year have the same number of students
B- I found tempting, but "eligible for selection" and "selected as soloist" are different. It could be that many attended the extra sessions and those 2 had something that stood out. This flaw is not made on two extremes like the stimulus we are trying to parallel.
C- This choice is actually proper logic. If honored-> band members who made deans list. Most band members-> honored. You can say Most band members-> made deans list
D- This choice mixes sufficient and necessary. In the first sentence biology majors is the necessary condition. In the second sentence, biology majors are sufficient to bring about the conclusion.
If anyone wants to correct me or add, much appreciated.

[maryadkins]

Your logic is right on. Nice job!

[jones.mchandler]

So "more than four" = "4 or more"? That doesn't seem right.

ETA: ok I think see the flaw now. The conclusion states that "most of the employees must have participated in fewer than four...events", when the employees could have participated in 4 or fewer (not just less than 4). Is that correct? If so, it clears up my question above too.

[WaltGrace1983]

So "more than four" = "4 or more"? That doesn't seem right.

ETA: ok I think see the flaw now. The conclusion states that "most of the employees must have participated in fewer than four...events", when the employees could have participated in 4 or fewer (not just less than 4). Is that correct? If so, it clears up my question above too.

Yes, that's correct.

Those and only those who went to more than 4 events were eligible for the raffle
+
Small proportion were eligible for raffle
→
Most went to less than 4 events

The argument is forgetting those that may have just gone to exactly 4 events. This would have been a valid argument if the conclusion was "Most went to 4 or less events."

(A) % does not equal number. Wrong flaw.
(B) Confusing necessary requirement (attending extra sessions) with a sufficient (concluding that those who fulfilled the requirement were the only people that did). Wrong flaw.
(C) Valid.
(D) Confusing necessary requirement (being a bio major) with a sufficient (concluding that being a bio major was sufficient, not necessary, for volunteering - maybe none of the bio majors volunteered). Wrong flaw.

[kimhyungjoon]

FLAWED PATTERN OF REASONING

Most employees participated in <4 scheduled events...
because all employees who participated in >4 events and only those were eligible for raffle...
and only a small proportion of all employees were eligible for the raffle.

Apparent flaw: what about those who participated in exactly four events?

Lesson
By the time you finished reading answer choice D, you might have started panicking that maybe you misunderstood the flaw. However, E indulges squarely in the dichotomous fallacy. A clear prephrase always helps.