What is the unit rate for the cans of lemonade

For shop smart, the price is 48 packs for 9 dollars so you would divide
9 ÷ 48 to find the price for dollars per can which is 19 cents per can
for super save it's saying 48 packs for 10 dollars so divide
10 ÷ 48 and that is 21 cents per can
for price buster it's saying 36 packs for 9 dollars so you would divide
9 ÷ 36 which is 25 cents per can
so Mei Pilar and David should purchase the cans at shop smart since it's cheaper

How am i goonna know explain