2002 AMC 10A Problems/Problem 9
Contents
[hide]Problem
There are 3 numbers A, B, and C, such that , and . What is the average of A, B, and C?
Solution
Notice that we don't need to find what and actually are, just their average. In other words, if we can find , we will be done.
Adding up the equations gives so and the average is . Our answer is .
Solution 2
As there are only 2 equations and 3 variables, just set one of the variables to something convenient, like 0. Setting C as 0, we get A is -2, and B is 11 by substitution. By basic arithmetic the average is 3=>B
-dragoon
See Also
2002 AMC 10A (Problems • Answer Key • Resources) | ||
Preceded by Problem 8 |
Followed by Problem 10 | |
1 • 2 • 3 • 4 • 5 • 6 • 7 • 8 • 9 • 10 • 11 • 12 • 13 • 14 • 15 • 16 • 17 • 18 • 19 • 20 • 21 • 22 • 23 • 24 • 25 | ||
All AMC 10 Problems and Solutions |
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