Question

An urn contains10 balls of equal size but distinguishable only by colour. 5 of the balls are blue, 3 are red and 2 are green. If a ball is selected at random, what is the probability that it will be a white ball?

Answer 1

There are 0 white balls among 10 balls, so probability of picking a white ball is ${\frac 0 {10}}=0$