how many different ways can 8 people be seated in 3 chairs

Answer 1

the first chair can be filled in 8 ways,
for each of those the 2nd chair can be filled in 7 ways, (one is seated)
and for each of those, the 3rd chair can be filled in 6 ways, so
number of ways = 8*7*6 = 336 ways

Answer 2

Use a permutation.

8! divided by (8-3)! = 336

Answer 3

1+2=336