From the Publisher:
For brainiacs and anyone who loves to start the day with a challenge, 365 Brain Puzzlers is filled with hundreds of puzzles that are tough enough to be sanctioned by Mensa, the internationally famous high-IQ society. There's Sum Triangle. Language Barrier. Use Your I's. Double Double Up. Plus word ladders, sequences, clever twists on crosswords and word searches, and more: Exactly 1/6 of a class of university freshmen has handed in the final English essay. When 20 more assignments come in, 1/4 of the class will have submitted the essay. How many students are in the class? Answers are printed on the reverse of each page of the calendar.