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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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What is the value of \[\dfrac{11!-10!}{9!}?\]
\(\)
Notation: \(!\) is the factorial notation. For example, \(8! = 1\times2\times3\times\cdots\times8 \).
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.
by
Jessey Uche-Nwichi
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John makes a cup of coffee, which is initially at a temperature of \(90^\circ\text{C}\). After 5 minutes, he notices that its temperature has dropped to \(80^\circ \text{C}\). How much more time will it take for the temperature of the coffee to further drop to \(70^\circ \text{C}\)?
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.
Used and loved by 4 million people
Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.
by
Rohit Gupta
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If you use all of the pieces to build a large square, what is its side length?
- one \( 6 \times 6 \) square
- two \( 5 \times 5 \) squares
- three \( 4 \times 4 \) squares
- four \( 3 \times 3 \) squares
- five \( 2 \times 2 \) squares
- six \( 1 \times 1 \) squares
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
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including olympiad champions, researchers, and professionals.
by
Profe Ronald
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\[\large \begin{array} { l l l l l } & &D & O & G\\ +& &C & A & T \\ \hline & 1 & 0 & 0 & 0 \\ \end{array} \]
The above shows a long addition, where each of the symbols represents a distinct single-digit positive integer.
What is the sum \( D + O + G + C + A + T ? \)
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.
by
Hana Nakkache
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Mario has to meet the Princess at the opposite node of the network, as shown above. The digit on each node indicates the number of coins he collects upon arriving at the node. He can visit each node only once.
For example, if Mario follows the red arrow trail illustrated below, he will obtain \(1+6+3+4=14\) coins before reaching the Princess.
To prove his love, the Princess demands that Mario collect exactly 17 coins (as that is her favorite number). Can Mario accomplish this task?
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.
by
Worranat Pakornrat
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