Bag A contains 3 red balls and 3 blue balls. Bag B contains 1 red ball and 3 blue balls.
A ball is taken at random from bag A and placed in bag
B. A ball is then chosen from bag B. What is the probability
that the ball taken from B is red?

30% probability that the ball taken from B is red.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

In this question:

Red ball from urn A:

3/6 = 1/2 probability of getting a red ball from urn A.

Then urn B will have 5 balls, 2 of which are red, so 2/5 probability of getting a red ball.

Blue ball from urn A:

3/6 = 1/2 probability of getting a blue ball from urn A.

Then urn B will have 5 balls, 1 of which is red, so 1/5 probability of getting a red ball.

Total:

3/10 = 0.3 = 30%.

30% probability that the ball taken from B is red.