Problem 2 · 2023 Math Kangaroo
Easy
Arithmetic & Operations
sum-constraint
The two markers with a question mark have the same value: \(20 + 10 + 10 + ? + ? + 1 = 51\). Which value do you have to use instead of the question mark so that the calculation is correct?
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Answer: C — 5
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Hint 1 of 2
Add up the numbers you can already read.
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Hint 2 of 2
Subtract that running total from 51, then split the leftover between the two equal markers.
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Approach: fill the known values, then split the remainder
- The known markers add to 20 + 10 + 10 + 1 = 41.
- The two equal question marks must make up 51 − 41 = 10.
- Since the two are equal, each is 10 ÷ 2 = 5.
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