Problem 30 · 2016 Math Kangaroo
Stretch
Spatial & Visual Reasoning
cube-viewscareful-counting
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Answer: A — Region A
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Hint 1 of 3
Count the black unit squares on the five visible faces, then see how many black cubes the sixth face must show.
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Hint 2 of 3
There are 15 black cubes in all; the five faces fix most positions, leaving a forced pattern for the sixth.
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Hint 3 of 3
Match that leftover black/white pattern to an option.
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Approach: account for all 15 black cubes
- The cube has 15 black and 12 white unit cubes; the five shown faces fix the positions of most black cubes.
- The sixth face must display exactly the remaining black cubes in their correct squares.
- Matching that forced pattern to the options gives region (A).
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