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5 times 5

Number Theory Level 2

$\large 5! - (5-1)! - (5-2)! - (5-3)!- (5-4)! = \, ?$

Notation: $!$ denotes the factorial notation. For example, $8! = 1\times2\times3\times\cdots\times8$ .

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Excel in math and science

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by Jefferson Conza

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