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Jan1-12, 05:11 AM
P: 79


-"random" means our choice is a uniformly distributed random variable
-the problem can have at most one correct answer even if it is stated by many possible choices
(for example, the answer can't be both 50% and 25% but it can be both A and D)

(attempt at a) solution:

*Let's suppose that A is the correct answer.
Then D is the correct answer also, since they state the same thing.

Therefore, the chance of hitting a correct answer is .5. Therefore, B is the correct answer which is contradictory. So A can't be the correct answer.

*Under the same reasoning, D can't be the correct answer

*Let's suppose B is the correct answer.
Thus the chance of hitting a(the) correct answer is .25. Thus A or D is the correct answer, which is contradictory.

*same goes with C

Therefore none of the above answers is correct.

That was fun! (or might still be if I got it wrong!)

Are my assumptions wrong?
Is the solution wrong?