For the first package, you take 26.25 and divide it by 5. That should get you 5.25 total per t-shirt in the first package. For the second package, same basic steps. you divide 14.25 by 3. That will give you a total of 4.75.
Package#1 unit price per t-shirt: 5.25
Package#2 unit price per t-shirt: 4.75