Perms and combs question (1 Viewer)

[sadpwner]

18. Find how many arrangements of the letters of the word UNIFORM are possible:
(d) if the M is somewhere to the right of the U.

Apparently, the answer is half of the total arrangements. Can someone explain why, and could you work it out another way?

 

[J280]

The answer is half the total arrangements because there are ultimately 2 cases: M can either be on the left or right side of U, but in this case it can only be on the right. Hence the answer is half of the total.