Question

There are 12 standbys who hope to get on your flight to Hawaii, but only 6 seats are available on the plane. How many different ways can the 6 people be selected?

Answer 1

Since order doesn't matter, we use the combination formula.

Explanation:

The combination formula is `(n!)/((n - r)!r!)`, where n is the total number of items (12) and r the number being picked at and x time (6).

`(12!)/((6!)(6)!)`

Calculating this we get 924. So, there are 924 ways of selecting 6 standbys from 12 standbys.

Practice exercises:

1. Among the following images, say in which events order does matter and in which it doesn't.

a)

b)

2 . How many ways are there of selecting 3 employees from a group of 11 seekers of employment?