Answer:
Jill can visit these 3 cities in 6 different orders.
Explanation:
As question clearly tells that Jill plan to visit 3 different cities M, L, and S.
She plans to visit each city exactly once and return to City C after 3 visits.
So the different orders in which she can visit 3 cities will be
M L S C
M S L C
L M S C
L S M C
S M L C
S L M C
In other words number of ways she can visit = 3! = 6
So there are 6 orders in which she can visit these three cities.