I need to know the proper way to solve this kind of problem:Five employees of a firm are ranked from 1 to 5 based on their ability to program a computer.Three of these employees are selected to fill equivalent programming jobs.If all possible choices of three (out of the five) are equally likely,then how can we find the following probabilities: a) The employee ranked number 1 is selected. b) The highest-ranked employee among those selected has rank 2 or lower. c) The employees ranked 4 and 5 are selected.
The correct answers are as follows: 6/10 or (36/60) ,4/10, 3/5
I am aware of that the formula for probability is s/n;where n is the total number of outcomes. I know how to get n by using $5_{P_3}$ (5 ways taking 3 at a time). Now, how do I get s (success outcome)? That confuses me. (I know that s(success outcome) is the number that will lock / target your condition) Thank you.