Question

A jar contains three red marbles and five green marbles. A marble is drawn at random and not replaced. A second marble is then drawn from the jar. Find the probability that the first marble is red and the second marble is green.

Answer 1

P(red then green) = 5/8 * 3/7 = 15/56

Step-by-step explanation: Since this is a logical "and" case, we have to multiply the separate events' probabilities...thus P(red then green) = 5/8 * 3/7 = 15/56

Answer 2

3/28

Explanation:

3 red+ 5 green = 8 marbles in the jar

1st marble:

P(red) = number of red/ total = 3/8

We keep the marble

2 red+ 5 green = 7 marbles in the jar

P(green) = number of green/ total = 2/7

P (red,keep,green) = P(red)* P(green) = 3/8*2/7 = 6/56 = 3/28