Combinatorics

Variations without Repetition

V(n,k) = n!/(n-k)!

  • High school
  • about 3 min
  • 8 of 11 in the family
Not started

Available elements (n = 5):

ABCDE

Filling 2 positions (no repetition):

5pos 1
×
4pos 2
= 20
V(5,2)=5!(5−2)!=5×4=20V(5,2) = \frac{5!}{(5-2)!} = 5\times4 = 20

Variations without repetition: ordered k-selections from n. Position 1: 5 choices, position 2: 4, etc.

Where it is taught