¶ 2009 AMC8 Problem 5
Problem:
A sequence of numbers starts with and . The fourth number of the sequence is the sum of the previous three numbers in the sequence: . In the same way, every number after the fourth is the sum of the previous three numbers. What is the eighth number in the sequence?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Make the list:
So the eighth number in the sequence is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions