Problem 7 · 2010 Math Kangaroo
Medium
Spatial & Visual Reasoning
spatial-reasoning
In the box there are seven blocks. By sliding the blocks around it is possible to make room so that one more block can be added. What is the least number of blocks that must be moved?
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Answer: B — 2
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Hint 1 of 2
Look at where the empty space is — it is split into pieces, not one block-sized hole yet.
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Hint 2 of 2
You only need to slide enough blocks to gather that empty space into one spot the new block fits.
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Approach: gather the empty space into one hole
- There is exactly one block of empty space, but it is spread out, so a new block will not fit yet.
- By sliding just two of the blocks, the scattered empty space lines up into a single block-shaped gap.
- The fewest blocks you must move is 2 (answer B).
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