Question

In a box are 3 red balls and 5 blue balls. From this box are drawn 4 balls and placed in a second box. Given the ball drawn from the second box is red, what is the probability that 2 red and 2 blue balls were transferred from box 1 to box 2?

Answer 1

Total number of balls = 3 + 5 = 8

The probability that 2 red and 2 blue balls were transferred from box 1 to box 2

The probability that the ball drawn from the second box is red

Given the ball drawn from the second box is red, the probability that 2 red and 2 blue balls were transferred from box 1 to box 2