2020 AMC 8 Problems/Problem 12
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For a positive integer , the factorial notation represents the product of the integers from to . What value of satisfies the following equation?
Solution 1
Notice that = and we can combine the numbers to create a larger factorial. To turn into we need to multiply by which equals to
Therefore, we have
We can cancel the 's, since we are multiplying them on both sides of the equation.
We have
From here, it is obvious that
-iiRishabii
See also
2020 AMC 8 (Problems • Answer Key • Resources) | ||
Preceded by Problem 11 |
Followed by Problem 13 | |
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