kevincanspain wrote:If Vernon was born several years ago in the month of March, did the month in which he was born have 4 Sundays? (March always has 31 days)

(1) The month in which he was born had 4 Fridays and 4 Mondays.
(2) The month in which he was born had 5 Tuesdays.

(1) Sufficient - there is only possible configuration of the days. The first Friday must have been on the 4th, and the first Monday must have been on the 7th. This means the first Sunday was on the 6th, and there would have been only four.

(2) Not sufficient - Tuesday could have been the first day of the month as in the example given above, in which case there would have been only 4 Sundays. However, Sunday could also have been the first day of the month, in which case there would be 5 Sundays & 5 Tuesdays.

Won't give it away, but a hint here: if you have 31 days, you really have 4*7 + 3 days. What could those three extra days be, given each statement?