(a)

(i) Find how many different 5-digit numbers can be formed using the digits \(1,3,5,6,8\) and \(9\). No digit may be used more than once in any 5-digit number.

(ii) How many of these 5-digit numbers are odd?

(iii) How many of these 5-digit numbers are odd and greater than \(60000\)?

(b) Given that

\(45\binom n4=(n+1)\binom{n+1}{5},\)

find the value of \(n\).