(a)[3]
Seven fair dice, each labelled $1,\,2,\,3,\,4,\,5,\,6$, are rolled and arranged in a row. Find how many arrangements are possible if the two end numbers have a total of $4$.
(b)[6]
Find the number of ways that $9$ different computer games can be divided between Wainah, Jingyi and Hebe so that every person gets an odd number of computer games.