I didn't know what forum to post this in so i chose Advanced algebra!

Given a code over the alphabet of q symbols with parameters (n,m,d) the sphere-packing bound gives an upper bound for the value of m in terms of n,d and q.

Show that there is no (6,15,5)- code over the alphabet with 3 symbols?

Find the largest value of m, for which there exists a (6,m,5) code over the alphabet with 3 symbols?