Solve:-
Find unit price per pack.
6-Pack:-
2.49 ÷ 6 = 0.41
$0.41 per can
12-pack:-
3.99 ÷ 12 = 0.33
0.33 per can
24-pack:-
5.49 ÷ 25 = 0.22
0.22 per can
The cheapest is 24-pack, because the unit price for that is the cheapest. After that pack is the 12-pack one because that is cheaper than the 6-pack. and last is the 6-pack.