| 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%. |
