From a box containing 2 red, 6 white and 5 black balls, a ball is randomly selected. What is the probability that the selected ball is black?
2/13
5/13
5/11
5/6
11/13
Correct answer is B
2r, 6w, 5b balls Total balls = 2 + 6 + 5 = 13 balls p(black) = 5/13