Question

Box A contain 5 green and 7 red balls Box B contain 3 green, 3 red and 6 yellow balls. A box is selected at random and a ball is drawn at random from it. what is the probability that ball drawn is green?

Answer 1

Answer:

1/3

Explanation:

There are 12 balls in Box A 5 of them are green which means the probability drawn a green ball  from Box A is 5/12, and 12 balls in Box B means the probability drawn a green ball from Box B is 3/12, the probability of selecting Box A is 1/2,  same as Box B so that the answer will be 1/2×5/12 + 1/2×3/12 = 1/3