An urn contains 4 red and 3 yellow marbles.If two marbles are randomly drawn without replacement,find the probability the second one is yellow,given that the first marble drawn is red.
E) none of the above

Question

Quizplus · Accepted Answer

We know that the first marble drawn is red, so there are now 3 yellow and 4 red marbles left in the urn. 
The probability of drawing a yellow marble as the second one is:
(3/6) = 1/2
Therefore, the probability that the second marble is yellow given that the first marble drawn is red is:
(3/6)/(4/7) = (1/2)/(4/7) = 7/8
So, the best choice is B) 11ea83f6_631a_902b_b5a5_f5e3bc54ed17_TB6578_11_TB6578_11

An Urn Contains 4 Red and 3 Yellow Marbles