Final answer:
Jan should buy 3 containers of sour cream for the party.
Step-by-step explanation:
To determine the number of containers of sour cream Jan should buy, we need to find the total number of cups she needs. She plans to make 5 recipes of dip, and each recipe calls for 1 cup of sour cream. Therefore, she will need a total of 5 cups of sour cream.
Sour cream is sold in 1-pint containers. Since there are 2 cups in one pint, Jan needs to buy 5/2 = 2.5 containers. However, she can only buy whole containers, so she should buy 3 containers of sour cream in order to have enough.