Combinatorics

Question 1

What are combinations + formula

Answer 1

Order does not matter y 5C3 es 5×4/2! Or 10C7 es 10×9×8/3!

Question 2

Permutations que son y formula

Answer 2

Order matters (example) and you can use factorial if no subsets or nPk = n!/(n-k)!

Question 3

Which rule can we use for permutations of repeated items (example: ways to create 4 digit codes using DIIG)

Answer 3

Mississippi (n!/subset 1!× subset 2!…)

Question 4

Circular arrangements, number of ways to set n items in a circle

Answer 4

(N-1)!

Question 5

Permutations with restrictions

Answer 5

Superset! × total!

Question 6

Combinations with restrictions

Answer 6

Ctotal - Copuesta

Question 7

Independent counting method

Answer 7

Number of items 1 × number of items 2 (si es una constante utilizas powers)