Permutation and Combination Problem

[sukhman]

A group of 5 students bought movie tickets in one row next to each other. If Bob and Lisa are in this group,what is the number of ways of seating if both of them will sit next to only one other student from the group? Answer 3 ! × 2 !

[Java_85]

Imagine there are 5 sits--> _ _ _ _ _
If bob and lisa will sit next to only one other student from the group, then each of them should be sitting in one end of row i.e. Bob _ _ _ Lisa or Lisa _ _ _ Bob ==>
Answer = 2(the mentioned states) * 3!(for the three empty spots in between). ==> 2! * 3!