I recently read your book and find it an interesting and helpful read. I found a couple of mistakes during some of the test-yourself questions though.
Since I didn't manage to get a hold of you or Mark Cade any other way, I'll be posting my notes in this comment.
Typo 1: On page 81, question 6. The Answer says D but the explanation below it explains why C is the correct answer (which it is indeed).
Typo 2: On page 95, question 1. The Answer says C and D but the correct answers are B and C, as is given in the explanation.
Typo 3: On page 148, question 5. The Answer says B, C and F while the actual answers are B, D and F.
Thanks for the otherwise great book!
Thanks for the comments. These are all typos that need to go into the errata for the book. I'll reach out to the publshers to see when the next run is and also create a blog post to call out these three for other readers. Thanks!