Problem:
How many whole numbers between and contain the digit
Answer Choices:
A.
B.
C.
D.
E.
Solution:
In addition to the numbers from , there are numbers ending in (e.g., ) and numbers with a ten's digit of (e.g., , ). But the numbers and are counted twice in this process, so there are a total of .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions