Asked by Anonymous
A bag contains 4 red and 3 black balls. A second bag contains 2 red and 4 black balls. One bag is selected at random. From the selected bag, one ball is drawn. Find the probability that the drawn ball is red.
Answers
Answered by
Reiny
consider the result as 2 independent events
bag1, red
bag2, red
Prob(bag1,red) = (1/2)(4,7) = 2/7
prob(bag2,red) = (1/2)2/6) = 1/6
prob(your event) = 2/7 + 1/6 = 19/42
bag1, red
bag2, red
Prob(bag1,red) = (1/2)(4,7) = 2/7
prob(bag2,red) = (1/2)2/6) = 1/6
prob(your event) = 2/7 + 1/6 = 19/42