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Cryptograms
Cryptograms are puzzles where some (or all) digits are missing from an arithmetic operation. Tinker with different combinations of numbers and letters to unlock the right answer.
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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Concept Quizzes
\[ \begin{array}{ccccc} & & & & A&B\\ \times & & & & &9 \\ \hline & & & C & 2 &3 \end{array} \]
Use the divisibility rules of 9 to find the value of \(C\).
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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by Brilliant Staff
\[ \begin{array} { l l l l }
& & & & \ 9 \\
\times & & & 3 & X \\
\hline
& & 3 & 3 & 3 \\
\end{array} \]
What digit \(X\) satisfies the cryptarithm above?
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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by Brilliant Staff
\[ \large{\begin{array}{ccccccc} && & & & & 5& P \\ \times && & & & &Q &R\\ \hline & & & & & 8& 0&0 \end{array}} \]
Knowing that \(800 = 2^5\times5^2\), find the value of the 2-digit integer \(\overline{QR}\).
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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\[ \large{\begin{array}{ccccccc} && & & & & 4& E \\ \times && & & & & 2&1 \\ \hline & & & & & F & 4 & 5 \end{array}} \]
Determine the value of \(F\).
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,
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\[ \large{\begin{array}{ccccccc} && & & & & & E \\ \times && & & & & &E \\ \hline & & & & & & 3 & E \end{array}} \]
Find the value of \(E\).
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.
Your answer seems reasonable.
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That seems reasonable.
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by Brilliant Staff