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[ptraye]

P: Sleep deprivation has been the leading non-narcotic cause of automobile accidents in this state for the last 5 years.

(A): (The leading narcotic cause of automobile accidents does not outnumber the leading non-narcotic cause.)

C1: For the last five years, most car accidents in this state were caused by sleep deprivation.

C2: In the last five years, at least as many car accidents were caused by sleep deprivation as by the most common narcotic cause.

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I chose C1, but C2 is correct. Can some1 explain this problem a bit?

Thanks.

[ohthatpatrick]

Like so many trap answers, C1 is wrong because of the word "most".

This question really tests the idea of a 'plurality' vs. 'a majority'.

Say that there was a Presidential election with 3 candidates.

The winner is the one who got the most votes of the 3 candidates. Does that mean the winner got most of the votes?

Do we know that the winner got more than 50% of the vote? No.

Maybe it looked like this:
winner - 45%
2nd place - 30%
3rd place - 25%

The winner got a plurality ... more votes than any other individual ... but not a majority.

It would be incorrect to say "more people voted for the winner than for someone else" or to say "most people voted for the winner".

After all, 45% voted for the winner while 55% voted for someone else.

Let's plug in some numbers to disprove C1:

P: Sleep deprivation has been the leading non-narcotic cause of automobile accidents in this state for the last 5 years.
(A): (The leading narcotic cause of automobile accidents does not outnumber the leading non-narcotic cause.)

Causes of accidents:
40% - sleep deprivation (non-narcotic)
30% - heroin (narcotic)
20% - texting (non-narcotic)
10% - crack (narcotic)

Okay, so sleep deprivation IS the leading non-narcotic cause.
The leading narcotic cause, heroin, does NOT outnumber sleep deprivation.

Is this true?
C1: For the last five years, most car accidents in this state were caused by sleep deprivation.

Nope, just 40%. 60% were caused by something else.

Is this true?
C2: In the last five years, at least as many car accidents were caused by sleep deprivation as by the most common narcotic cause.

Yes. Sleep deprivation caused 40%. Heroin, the most common narcotic cause, was only 30%.

What you probably wanted C1 to say (and what WOULD be a valid inference), is that "nothing else has caused more accidents than sleep deprivation has over the last five years".

Hope this helps.