SOLUTION
Question a: The correct way to get the ways 5 colors can be chosen from 13 colors is by using the combination formula since order does not matter; We have:
[tex]\begin{gathered} 13C5 \\ nCr=\frac{n!}{(n-r)!r!} \\ 13C5=\frac{13!}{(13-5)!5!} \\ \frac{13!}{8!5!}=\frac{13\times12\times11\times10\times9\times8!}{8!\times5!}=\frac{154440}{120}=1287 \end{gathered}[/tex]
Hence, the number of ways 5 colors can be chosen from 13 colors if the order does not matter is 1287 ways.
Question b: The correct way to get the ways 5 colors can be chosen from 13 colors is by using the permutation formula order does matter; We have:
[tex]\begin{gathered} 13P5 \\ nPr=\frac{n!}{(n-r)!} \\ 13P5=\frac{13!}{(13-5)!} \\ =\frac{13!}{8!} \\ =\frac{13\times12\times11\times10\times9\times8!}{8!}=154440 \end{gathered}[/tex]
Hence, the number of ways 5 colors can be chosen from 13 colors if the order matters is 154440 ways.