My school currently teaches the IB Math SL (formerly "Math Methods") course over two years, and at the halfway point last year, I wanted to give my students a final exam. All 60 of the questions are multiple-choice, and I've included a key by using Word's "Comments" feature.
Note: when you download the word file, you will probably see the version that includes comments. To turn off the comments (so you can print it out for your students), click on the "review" tab, and then change "final showing markup" to "final."
On the other hand, toggling back will turn them back on, which will reveal the answers for you.
Please download the pdf preview file first, so you can see exactly what's included; the product file is a word document, which you may personalize for your students.