I have two questions. I'm not sure if I'm allowed to post two at once so I'll start with one
"Twenty boys and twenty girls are to take a ride on a Ferris wheel with twenty pods. How many ways can they be arranged if each pod is to contain one boy and boy girl"
For circular arrangements, (n-1)! possible arrangements
The Attempt at a Solution
1. Fix the first boy, sort of the other 19 around him... 19! ways
2. Now, with all the spots set in terms of the first boy, sort the 20 girls... 20! ways
3. Thus, there are 20!*19! ways to sort them
I am pretty sure this is correct but I can't find my notes so I do not know for sure.