# The director of a government agency has been given a list of 12 firms cited for unfair labor practices. Because of staff shortage and inefficiency, only one-fourth of these 12 can be charged. How many possible sets of 3 firms can be charged?

##### 1 Answer

Feb 26, 2017

220 sets

#### Explanation:

This is a combinations question - we don't care in which order we pick the 3 firms (picking firms A, B, C is the same as picking firms C, B, A). And so we can solve this with the combinations formula, the general formula of which is: