1989 AMC 8 Problem 23
Attempt Problem 23 of the 1989 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 1989 AMC 8 solutions, or check the answer key.
All problems are used with official legal permission of the Mathematical Association of America (MAA).
23.
An artist has cubes, each with an edge of meter. She stands them on the ground to form a sculpture as shown. She then paints the exposed surface of the sculpture. How many square meters does she paint?
Answer: C
Small hint:
Count the exposed faces on the four vertical sides, then the faces seen from directly above
Big hint:
Each of the four sides shows exposed faces, and looking straight down covers the full footprint of top faces
Solution:
Because each higher layer is flush into one corner, each of the four vertical sides shows a stepped profile of exposed square faces, for side faces.
Viewed from directly above, the top faces cover the full footprint, adding more faces. The bottom rests on the ground and is not painted, so the total is square meters.
Thus, the correct answer is C .
Problem 23 in other years
- 1985 AMC 8
- 1986 AMC 8
- 1987 AMC 8
- 1988 AMC 8
- 1990 AMC 8
- 1991 AMC 8
- 1992 AMC 8
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