What is the solution to problem 6 in the Combinatorics seating problem?

[EvLer]

Hello,
so this is what I am stuck on:
In how many different ways can you seat 11 men and 8 women in a row so that no two women are to sit next to each other.

I know it's going to be combination and not permutation and that total number of seating them is 11!*8! but that is as far as I could get

 

[buddyholly9999]

Look at problem 6 for help.
http://www.math.ksu.edu/~zlin/m510/ex1sol.pdf