posted by Kay .
If a bag contains 50 marbles with 28 red ones and 22 blue ones. A marble is picked at random from the bag.what is the probability of picking a red marble after a blue marble was picked first?
after we know that a blue one was picked, there are 21 blues left out of the remaining 49 marbles but still 28 reds, so
prob(next one red) = 28/49