This is a fun April Fools math activity. Fun for the teacher that is. The problems make sense to try and use mathematical principles, but the answers are non-mathematical.
Want to watch them work really hard? Tell them that in all of your years of teaching no student has every gotten a perfect paper. Post a reward for the student who gets half of them correct. It is fun to watch them work hard to figure out the answers and then they get to the last question and realize they have been had. It's all in good fun though.