how many 3-digit numbers have exactly 2 digits that are the same?

Answer 1

Answer is 243

Starting at 100 (the first 3-digit number), I counted all numbers that had exactly two digits that were the same. I did this through 199. There are 27 of these. I then multiplied that result by 9 (to pick up the 200s through 900s).

got that from google :)

Answer 2

Starting at 100 (the first 3-digit number), I counted all numbers that had exactly two digits that were the same. I did this through 199. There are 27 of these. I then multiplied that result by 9 (to pick up the 200s through 900s).