2018 AMC 12B Problems/Problem 9
Problem
What is
Solution 1
We can start by writing out the first couple of terms:
Looking at the second terms in the parentheses, we can see that occurs times. It goes horizontally and exists times vertically. Looking at the first terms in the parentheses, we can see that occurs times. It goes vertically and exists times horizontally.
Thus, we have:
This gives us:
Solution 2
Solution 3
Solution 4
The minimum term is , and the maximum term is . The average of the terms is the average of the minimum and maximum terms, which is . The sum is therefore
See Also
2018 AMC 12B (Problems • Answer Key • Resources) | |
Preceded by Problem 8 |
Followed by Problem 10 |
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All AMC 12 Problems and Solutions |
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