calculate the probability that the first ball drawn at random will be yellow.

Question

A bag contains 5 yellow balls and 7 white balls. 1.Calculate the probability that the first ball drawn at random will be yellow?2.Calculate the probability that the first ball drawn at random will be white? 3.Calculate the probability that for the second draw you will get white if the first ball was white and was returned to the bag before the second draw was made?. 4.Calculate the probability that for the second draw you will get white if the first ball was white and was not returned to the bag?

Answer 1

1. 5/12
2. 7/12
3. 7/12 the chances for the second draw are not affected by the result of the first draw.
4. One white removed leaves 6 white and 11 balls in all. Probability=6/11.