Question

A pouch contains 6 red marbles and 2 blue marbles. A second pouch contains 3 red marbles and 7 blue marbles. A marble will be drawn at random from the first pouch and placed in the second pouch without its color being noted. Then a marble will be drawn from the second pouch. If the second marble is​ red, what is the probability that the first marble drawn is​ blue?

Answer 1

2/8

Explanation:

because there are 2 blue marbles

add those up with the red marbles(6) and you get 8 marbles. But the chance for picking up a blue marble would be 2/8