Problem 5 · 2022 Math Kangaroo
Easy
Arithmetic & Operations
division
Marbles are sold in packages of 5, 10 or 25. Tom buys exactly 95 marbles. What is the minimum number of packages Tom has to buy?
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Answer: B — 5
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Hint 1 of 2
To use few packages, lean on the biggest size (25) as much as possible.
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Hint 2 of 2
After taking as many 25s as fit, make up the rest with 10s and 5s.
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Approach: use the largest packages first
- Three packages of 25 give 75 marbles.
- The remaining 95 minus 75 = 20 marbles are two packages of 10.
- That is 3 + 2 = 5 packages, and no smaller count reaches exactly 95.
- So the minimum is 5.
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