Average number, combinatorics

Please help me solve these problems.

1. Nine boys and fourteen girls are arranged in a row in all possible ways. What is the average number of "neighbours" of opposite sex.

2. Consider a family of all $k$ -element subsets of a set $\left\{ 1,2,......,2n\right\}$ . For every such set consider its smallest element. Find the average value of the smallest element in all $k$ -element subsets.