What fraction of all the 10-digit numbers with distinct digits have the property that no two odd digits are neighboring?
Hello Guest,
like 1234567890. For the first digit there are 10 possibilities, for the second digit only 9 possibilities, for the third digit 8 possibilities,... and that makes 10! if you multiply all of them. There are only 2 possibilities that it is odd and even or even and odd, so \(\frac{10!}{2}=1814400 \mbox{ possibilities}\) .
Straight