Math concepts used: Combinatorics, binomial theorem.
Background: I ate at a Chipotle restaurant a few days prior to giving the exam. The inspiration came from looking at the restaurant's menu.
What I did: Wrote a pure combinatorics problem to see if students could utilize what they learned in the first week of MATH 3160. Also, it helped them understand the complexity of customized orders at a fast casual restaurant.
Aftermath: Not much.