This is a bit off topic too, but I thought you all might be interested that there is a new use for Pascal’s Triangle.
I came up with the question, please scroll down five messages to see how this relates to Pascal’s Triangle:
You have a combination padlock with four dials on it. Each dial has the numbers 0 through 4 on them. The lock can have as many 0s as dials, and is set to 0000 by default. The lock does not allow you to use any number between 1 and 4 two or more times in the combination. The following combinations are valid: 0123 1234 0103 0010 4031. The following combinations are invalid: 0113 4014 0202 4444. How many possible combinations are there?
