Answer:
a) 677,040 b) 17,160
Explanation:
a) this is a combinations problem as it deals with selection, rather than order. you can use a calculator to solve this:
there are 65 objects (colors) taken 4 at a time
(see photo)
there are 677,040 possible ways to arrange the boxes.
b) unlike question a, this is a permutation. the order matters.
since Ali can only visit the cities once, you must multiply by decreasing values starting from 13 down to 10 (4 "slots" for the 4 days)
13*12*11*10 = 17,160 possiblities