Brain Teasers and Puzzles

A box for your workings out:

Hint: This question involves the months in some way.

Answer: 431.

This is the sequence of the length of the name of the month and the number of days in that month. For example, January has 7 letters and 31 days: 731. February has 8 letters and 28 days, etc. The next 3 digits are therefore 431 since July has 4 letters and 31 days.