[tex] \huge \boxed{ \fcolorbox{black}{aqua}{Answer}}[/tex]
There are a total of 6 x 6 = 36 possible outcomes when a fair die is rolled twice. Of the 36 possible outcomes, there are 6 doubles: 1-1, 2-2, 3-3, 4-4, 5-5, and 6-6. Thus, the probability of getting a double is 6/36 = 1/6.