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Rewrite them in terms of combination maybe?

Number Theory Level 2

Let \(n! = 1\times2\times3\times \cdots\times n\).

Which of the following numbers is the smallest?

\[ 4!\times9! \] \[ 5!\times8! \] \[ 6!\times7! \]

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Excel in math and science

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by Pi Han Goh

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