Respuesta :

Answer:

84

Explanation:

combinations

permutations

9 total number of objects

3 sample

nCr = ( n r ) = n!/(r!(n-r)!)

9C3

9!/(3!(9-3)!

9!/(3!*6!)

(9*8*7*6!)/(3*2*1)*(6!)

(9*8*7)/(3*2*1)

(3*4*7)/(1)

84/1

tutorial

https://www.tiger-algebra.com/en/solution/combination-without-repetition/c(9,3)/

gathmath

byjus