20: The middle digit [**] from Wes Carroll's Puzzler

20: The middle digit [**]

2 minutes Posted Aug 28, 2016 at 4:00 am.

0:00

2:51

Share at current time

Show notes

How many three-digit numbers satisfy the property that the middle digit is the average of the first and the last digits?

//

Spiciness: ** out of ****