How To: Absurd Scientific Advice for Common Real-World Problems is a blend of science/math and humor. I bought my copy new.
Review:
How To is very similar to Munroe's What If? volumes, in that it examines hypothetical scenarios and attempts to determine, scientifically, if they are possible and what some of the unintended outcomes might be. In this case, however, the hypothetical scenarios are all addressing common real-world problems, like making friends, digging a hole, playing football, etc., although they're all taken to extremes in some way. And okay, so there are a few less common problems thrown in, like how to build a lava moat and how to mail a package from space.
I found this to be just as entertaining and fascinating as Munroe's What If? volumes. I enjoy seeing how he thinks his way through the various problems. His stick figure illustrations add to the humor. This time around there were some fun guest contributions too. I got a kick out of the thought of Serena Williams agreeing to see how many tries it would take her to knock a drone out of the sky with a tennis ball. Dr. Katie Mack's "vacuum decay no, tiny black hole yes" answer was also fun. Astronaut Chris Hadfield essentially got a whole chapter to himself, tackling every emergency landing situation Munroe could throw at him (granted, some of the answers generally boiled down to "you'll almost certainly die, but doing [blank] would help improve your chances of survival very slightly").