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There are 5 competitors in a race (John, mary and...

This topic has 2 expert replies and 0 member replies

There are 5 competitors in a race (John, mary and...

Post Thu Nov 09, 2017 12:07 pm
There are 5 competiros in a race (John, Mary and 3 other ones) in which there are no ties, what is the probability that Mary finish ahead of John?

A) 1/6
B) 1/3
C) 1/2
D) 2/3
E) 5/6

The OA is C.

Please, can any expert assist me with this PS question? I don't have it clear and I appreciate if any explain it for me. Thanks.

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DavidG@VeritasPrep Legendary Member
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Post Thu Nov 09, 2017 1:32 pm
AAPL wrote:
There are 5 competiros in a race (John, Mary and 3 other ones) in which there are no ties, what is the probability that Mary finish ahead of John?

A) 1/6
B) 1/3
C) 1/2
D) 2/3
E) 5/6

The OA is C.

Please, can any expert assist me with this PS question? I don't have it clear and I appreciate if any explain it for me. Thanks.
Well, if we assume that the outcomes are all random, then there are only 2 possibilities: Mary finishes ahead of John or John finishes ahead of Mary, so there's a 1/2 chance that Mary finishes ahead of John. (Of course, if one of them is actually faster than the other, well that would create a bit of uncertainty.)

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Post Thu Nov 09, 2017 7:07 pm
DavidG@VeritasPrep wrote:
(Of course, if one of them is actually faster than the other, well that would create a bit of uncertainty.)
No uncertainty here: if I'm getting even odds, give me the faster runner for the max. Cool

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