How many different ways can 2 students be seated in a row of 7 desks, so that there is always at least one empty desk between the students?
Choose the correct choice from the following:
A) 2 B) 3 C) 30 D) 6 E) 12
15 ways to seat the students:   with two empty seats between   1 empty w/ one student on the left most   1 empty....right most   two students can be interchanged   15x2=30   30
<result>C</result>
How many different ways can 2 students be seated in a row of 7 desks, so that there is always at least one empty desk between the students?