SOLUTION: how many 3 digit numbers can be formed is the leading digit cannot be 0?

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Question 382715: how many 3 digit numbers can be formed is the leading digit cannot be 0?
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
There are nine digits (0-9) for the hundreds' digit, and 10 choices for the tens' and units'. This leaves 9*10*10 = 900.
Or, we can count the number of three digit numbers in the base-10 counting system. It ranges from 100 to 999, so the number of elements in the set {100, 101, ..., 999} is 900 (since the set is inclusive).