Question

There are 4 red marbles and 3 blue marbles in a bag. Once a marble is drawn it is not replaced. Find the probability of drawing two red marbles in a row.

Answer 1

2/7

Explanation:

4 red marbles and 3 blue marbles in a bag = 7 marbles

P(red) = red/total = 4/7

No replacement

3 red marbles and 3 blue marbles in a bag = 6 marbles

P(red) = red/total = 3/6 = 1/2

P(red, no replacement, red) = 4/7 * 1/2 = 2/7