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Excel in math and science
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Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
Used and loved by 4 million people
Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.
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The diagonal lines join a vertex to the midpoint of the edge.
What fraction of the regular hexagon is shaded?
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
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including olympiad champions, researchers, and professionals.
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Chung Kevin
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5 years ago, the ratio of a father's and his son's ages was 3:1.
15 years from now, the ratio will be 2:1.
What is the father's current age?
Excel in math and science
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It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
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examples, and problems from the community.
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Munem Sahariar
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I have 3 nickels, 2 dimes, 2 quarters, and 2 half-dollars in my pocket.
If I randomly pull out 4 coins simultaneously, what's the probability that exactly 2 nickels are included?
\(\)
Note: Nickels, dimes, quarters, and half-dollars are all American coins.
Excel in math and science
Master concepts by solving fun, challenging problems.
It's hard to learn from lectures and videos
Learn more effectively through short, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
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Brilliant Member
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If \(a, b,\) and \(c\) are distinct numbers, is it possible that
\[ a + 2b < b + 2c < c + 2a ? \]
Excel in math and science
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It's hard to learn from lectures and videos
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Our wiki is made for math and science
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Chung Kevin
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You have an empty notebook with 96 sheets. Each sheet is numbered on both sides, with the page numbers ranging from 1 to 192 (inclusive).
Is it possible to rip out 25 sheets such that the sum of the page numbers on these sheets is exactly 1990?
Excel in math and science
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It's hard to learn from lectures and videos
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Our wiki is made for math and science
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Victor Paes Plinio
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