(a) A 5-character code is to be formed from the letters \(A,B,C,D,E,F\) and the numbers \(1,2,3,4,5,6,7\). Each character may be used once only in any code.

Find the number of different codes in which no two letters follow each other and no two numbers follow each other.

(b) A netball team of \(7\) players is to be chosen from \(10\) girls. \(3\) of these \(10\) girls are sisters. Find the number of different ways the team can be chosen if the team does not contain all \(3\) sisters.