Question

Mrs.Johnson has 14 blue pens, 7 black pens and 5 red pens in a desk drawer. If she Selects two pens at random without replacing them what is the probability that she selects a blue pen and then a black.pen

Answer 1

8.6

Explanation:

first you add all the numbers, then divide by 3 and you get 8.6.

Answer 2

P (blue | black) = 0.151

Explanation:

We know that there are 14 blue pens, 7 black pens and 5 red pens in Mrs. Johnson's desk drawer.

We are to find the probability of getting a blue pen and then a black pen when choosing two pens randomly without replacement.

Total pens = 14 + 7 + 5 = 26

P (blue pen) = 14/26

P (black pen) = 7/25

P (blue | black) = 14/26 * 7/25 = 49/325 or 0.151