Summer Teacher Challenge: Math Logic Puzzle from Mr. Schultz

Our ILS faculty invite our students (and parents!) to challenge themselves a bit this summer with our new Summer Teacher Challenge series! We'll be sharing a variety of puzzles and challenges from our ILS teachers that we invite you to solve. Students, share your solutions in the comments section for each challenge, and you could win a prize (please see our first challenge for more information on our great prizes!).

This challenge from the National Mathematics Competition (1991) was shared by our Upper School math teacher, Mr. Schultz. Use your math and logic skills to try and come up with the answer, and share your solution in the comments!

Three days ago, yesterday was the day before Sunday. What day will it be tomorrow?