2004 AMC 8 Problem 9
Attempt Problem 9 of the 2004 AMC 8 below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2004 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
9.
The average of the five numbers in a list is The average of the first two numbers is What is the average of the last three numbers?
Answer: D
Small hint:
Turn each average into a sum.
Big hint:
Subtract the sum of the first two numbers from the sum of all five.
Solution:
The sum of all numbers is The sum of the first numbers is
The sum of the last numbers is The average is therefore
Thus, D is the correct answer.
Problem 9 in other years
- 1985 AMC 8
- 1986 AMC 8
- 1987 AMC 8
- 1988 AMC 8
- 1989 AMC 8
- 1990 AMC 8
- 1991 AMC 8
- 1992 AMC 8
- 1993 AMC 8
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