Question
The numbers from 1 to `10^9` (inclusive) are written on the board. The numbers divisible by 3 are written in red, and the rest of the numbers are written in blue. The sum of all the red numbers is equal to `X`, and the sum of all the blue numbers is equal to `Y`. Which number is larger, `2X` or `Y`, and by how much?
Difficulty level (1 very easy - 10 very hard): 2
Topics:
Arithmetic
Number Theory
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Modular Arithmetic / Remainder Arithmetic
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Divisibility Rules
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Divisibility Rules by 3 and 9
Logic
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Reasoning / Logic
Algebra
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Sequences
Algebra
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Inequalities
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Averages / Means
Number Theory
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Division
- Beno Arbel Olympiad, 2017, Grade 8 Question 2
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