Problem 3 · 2017 Math Kangaroo
Easy
Spatial & Visual Reasoning
spatial-reasoning
Two square sheets are made up of see-through and black little squares. Both are placed on top of each other onto the sheet in the middle. Which shape can then still be seen?
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Answer: E
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Hint 1 of 2
A picture is visible only where BOTH sheets are see-through over that cell.
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Hint 2 of 2
Find the one cell that is clear (white) on the left sheet AND clear on the right sheet.
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Approach: a shape shows only through a cell that is transparent on both sheets
- Lay the two patterns on top of each other, cell by cell, over the middle sheet.
- A cell stays see-through only when BOTH sheets are clear there; if either sheet has a black square, that cell is blocked.
- Colour in every cell that is black on either sheet, and the cells still see-through show the picture.
- That picture matches choice E.
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