Week 8

 A permutation concerns situations where order matters, whereas a combination concerns situations where order does not matter. 

I.E.:

Families of maniraptorans in order of geological age involves permutations, because the order in which they're presented matters. 

Families of maniraptorans involves combinations, because the order in which they're presented does not matter. 

(13 is mistakenly labeled as 12 in my work)