In a panel discussion with 3 industry reps, 2 government reps, and 1 association rep, how many ways can they be seated along a row
a) with no restrictions (each person can sit anywhere)?
b) if the 3 industry reps must sit together (in any order) to the right of the others (also in any order)?
c) if, prior to sitting, each of the industry reps is paired up with a partner and these pre-assigned (or fixed) pairs must stay together and sit beside one another?