Problem:
The Fibonacci sequence starts with two 1 s, and each term afterwards is the sum of its two predecessors. Which one of the ten digits is the last to appear in the units position of a number in the Fibonacci sequence?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The sequence of units digits is
The digit 6 is the last of the ten digits to appear.
The problems on this page are the property of the MAA's American Mathematics Competitions