Question

what does the following expression mean?

\\7!\\

\\7 + 6 + 5 + 4 + 3 + 2 + 1\\

\\7 \cdot 6 \cdot 5 \cdot 4 \cdot 3 \cdot 2 \cdot 1\\

Explanation:

Define the factorial operation

$$ n! = n \cdot (n-1) \cdot (n-2) \cdots 2 \cdot 1 $$

Apply the definition to 7!

$$ 7! = 7 \cdot 6 \cdot 5 \cdot 4 \cdot 3 \cdot 2 \cdot 1 $$

Answer:

• \(7 + 6 + 5 + 4 + 3 + 2 + 1\)
• \(7 \cdot 6 \cdot 5 \cdot 4 \cdot 3 \cdot 2 \cdot 1\) (Correct answer)