Question

Harry has 2 blue pens, 2 black pens and 4 red pens in his box. He picks one pen and records its color, then puts it back in the box and draws another pen. What is the probability of taking out a red pen followed by the blue pen

Answer 1

1/8

Explanation:

Given:

• 2 blue pens
• 2 black pens
• 4 red pens

=> the total pens: 2+2+4 = 8

The probability of taking out a red pen is: 4/8

Because the is replacement when you put the red back in the box and the sum of pen is unchanged.

So the probability of taking out a blue pen is: 2/8

So the probability of taking out a red pen followed by the blue pen is:

4/8 * 2/8 = 1/8

Hope it will find you well.