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Figure This!

Quick Answer:

About 22%.


Complete Solution:

With two people, the probability that the second person’s birth month does not match the first person’s is 11/12.

A third person could be born in any of the other ten months and not match the first two. The probability that the third person’s birth month will not match either of the other two is 10/12. The probability that all three have different birth months is:

Continuing this process, the probability that six people have different birth months is:

Thus, the probability that at least two of the six people do not have the same birth month is about 22%.



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