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Old 12-22-2005, 06:38 PM
AaronBrown AaronBrown is offline
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Join Date: May 2005
Location: New York
Posts: 505
Default Re: OT: Blind Guess on a Test!

You are correct that there are dependencies, but this only helps you if you have some idea about the answers 1 and 2.

For example, if you think that 1 has a 60% chance of being true and 2 has a 30% chance, then

A. 1 only, 30% to 60%
B. 2 only, 0% to 30%
C. Both, 0% to 30%
D. Neither, 10% to 40%

So A has to be a better guess than B or C. D is only a better guess if you think that if 2 is true then 1 has at least 2/3 chance of being true.

You can also think about the psychology of the test maker. Straightforward professors will ask a question like this most often if the answer is both (this is not as reliable if there are a series of questions like this). Devious ones like to make it neither. Rarely will it be only 1 or only 2, unless there is more than one question of this type.
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