The last wednesday in a certain month is on the 26th day of that month. What day of the week is the first day of that month?

Let’s determine the first Wednesday. This would be 26 - 7n until we reach a number between 1 and 7. Thus, this would be 26 - 7 (3) = 5. Thus, the 5th day of that month was a Wednesday. 4th = Tuesday, 3rd = Monday, 2nd = Sunday, and 1st = Saturday. Thus, the first day of the month was Saturday.