Problem:
When counting from to , is the number counted. When counting backwards from to , is the number counted. What is ?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The number is the number counted when proceeding backwards from to . In turn, is the number, is the number, and is the number. Therefore is the number, which is the number.
The problems on this page are the property of the MAA's American Mathematics Competitions