### Instruction: On a Tuesday, a magician said, ``I made my wife disappear 31 days ago.'' What day of the week did he make her disappear?### Response: I need to figure out what day of the week it was 31 days ago.
I could use a calendar, but that might be tedious.
I notice that 31 days is 4 weeks plus 3 days.
That means that if I go back 4 weeks from Tuesday, I get another Tuesday.
Then I just need to go back 3 more days to get the day of the disappearance.
Going back from Tuesday, I get Monday, Sunday, and then Saturday.
So he made her disappear on a Saturday.