Respuesta :
Answer:
D.36
Step-by-step explanation:
Remember, the formula to calculate combinations is nCr = n! / r! * (n - r)!, where n represents the number of items, and r represents the number of items being chosen at a time.
Answer:
D. 36
Step-by-step explanation:
The formula for a combination :
- ⁿCₓ = n! / (n - x)! x!
Here we have ⁹C₇.
- ⁹C₇ = 9! / (9 - 7)! 7! = 9! / 2! x 7!
- 9 x 8 x 7! / 2! x 7!
- 9 x 8 / 2
- 36