Correct Answer:
A. 720
The correct answer is 720. The factorial notation (!) means multiplying all positive integers from the number down to 1. The expression 10! / 7! can be simplified by expanding the factorials and cancelling common terms.
Step-by-Step Solution
- Expand the Factorials:
10! = 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1
7! = 7 × 6 × 5 × 4 × 3 × 2 × 1 - Cancel the Common Factor 7!:
10! / 7! = (10 × 9 × 8 × 7!) / 7!
The 7! in the numerator and denominator cancel out completely. - Multiply the Remaining Numbers:
10 × 9 × 8 = 720 - Verification:
10! = 3,628,800 and 7! = 5,040.
3,628,800 ÷ 5,040 = 720. Confirmed.
Thus, 10! / 7! equals 720.