At the movies Lucinda bought food for herself and her friend

At the movies, Lucinda bought food for herself and her friend Rae, including: 1 box of popcorn to share at $5 a box, 1 box of Junior Mints for each of them at $2 a box, and 1 soft drink for each at $3 apiece. Rae bought a ticket for each at $7 apiece. Who spent the most money and by how much?

First, simplify the problem:

L = $5 + $4 + $6 = $15;