2007 AMC 8 Problem 9
Attempt Problem 9 of the 2007 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 2007 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
9.
To complete the grid below, each of the digits through must occur once in each row and once in each column. What number will occupy the lower right-hand square?
cannot be determined
Answer: B
Small hint:
Use the row and column restrictions to force entries one at a time.
Big hint:
Start with the last square in the second row, then move to the top-right square.
Solution:
The last square in the second row must be , since that row already contains and , and the last column already contains .
Then the top-right square must be , since the top row already contains and , and the last column already contains and .
This forces the to be in the bottom-right square.
Thus, B 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
- 1994 AMC 8
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- 1998 AMC 8
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