Problem 8 · 2025 Math Kangaroo
Medium
Spatial & Visual Reasoning
foldingnet-folding
There are numbers on the middle part of a 3-part unfolded card. The left and right parts of the card have holes. Mike folds the right part along the dotted line onto the middle part. He can now see the numbers 2, 3, 5 and 6 through the holes. Then he folds the left part along the dotted line onto the other two parts. What is the sum of the numbers that he can still see through the holes?
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Answer: A — 8
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Hint 1 of 2
After folding the right flap, you already see 2, 3, 5 and 6 through its holes.
Still stuck? Show hint 2 →
Hint 2 of 2
Folding the left flap on top covers some of those holes; only the numbers under a left-flap hole stay visible.
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Approach: trace which holes still line up after both folds
- After the right flap is folded over, its holes already let Mike see 2, 3, 5 and 6 on the middle panel.
- When the left flap folds on top, its holes only line up over some of those numbers: two of them stay showing through a hole and the other two get covered by solid paper.
- The two numbers still visible through a hole are 3 and 5, so the sum is 3 + 5 = 8, giving the answer (A) 8.
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