Problem 8 · 2025 Math Kangaroo
Easy
Logic & Word Problems
work-backwardsum-constraint
The picture shows the menu of a burger restaurant. The rain has washed away some of the numbers. The burgers are listed by price in increasing order, the cheapest being the “veggie” burger. What is the smallest possible price of the “deluxe” burger?
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Answer: B — 6.80
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Hint 1 of 2
Only the cents are readable; the whole-euro parts are hidden, but the prices increase down the list.
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Hint 2 of 2
Step down the menu choosing the smallest whole-euro part that keeps each price above the one before it.
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Approach: build the cheapest increasing price chain
- Prices rise: veggie 3.70 < classic _.30 < hot bacon _.60 < cheesy _.50 < double _.10 < deluxe _.80.
- Smallest classic above 3.70 is 4.30; then hot bacon 4.60; cheesy must beat 4.60 so 5.50; double beats 5.50 so 6.10.
- Deluxe must beat 6.10 and end in .80, so the least it can be is 6.80, which is (B).
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