Question

Two marbles are chosen, one at

a time, from a bag containing 6 marbles,4 red marbles and 2 green marbles. Suppose the first marble chosen is green. Is the probability that the second marble will be red greater if the first marble is returned to the bag or if it is not returned to the bag? Explain.

Answer 1

P(red) when the green marble is not return to the bag is greater

Explanation:

P( red ) = ?

Case the green marble is returned to the bag.

Bag: 4 red + 2 green = 6 marbles

P(red) = 4/ 6

Case the green marble is not return to the bag.

Out: 1 green marble

Bag: 4 red + 1 green = 5 marbles

P(red) = 4/ 5

4/5 > 4/6

P(red) when the green marble is not return to the bag > P(red) when the green marble is returned to the bag