If 1 green and 1 blue ball are taken from the box, then there are 10 green, 5 blue and 3 white balls, a total of 18 balls. If one ball is selected at random, the probability that it is green is given by 10 / 18
There are 20 balls in a box: 11 balls are green, 6 are blue and 3 are white. Then 1 green and 1 blue balls are taken from the box and put away. What is the probability that a green ball is selected at random from the box?

- 1/13
- 10/18
- 3/13
- 5/13
- 6/13