Question

How many ways can 3 students be arranged into 3 chairs?

Answer 1

Since order doesn't matter, if one student can go to any seat, then there are 3 ways to sit a student in one chair. Thus, there are 3*3*3=27 ways to arrange 3 students into 3 chairs by the Fundamental Counting Principle.

Answer 2

the same student cannot be in more than one chair at a time.
There are 3! ways to arrange 3 things

Answer 3

there are 18 chance to this three students to sit on the three chairs
because s1 is 1st chair the other two students are two chance to sit on the rest chairs each the same to this 2nd chair so
= 1+1 +1+1 +1+1 +1+1 +1+1 +1+1 +1+1 +1+1 +1+1 = 18