375,838 views
17 votes
17 votes
Gina has a box of pens that contains 10 red pens, 8 blue pens, and 2 green pens. She will randomly take out apen, write down the color, and put the pen back into the box. What is the probability that Gina will pull two redpens in a row?

User Jackie Yeh
by
2.1k points

1 Answer

19 votes
19 votes

10 red

8 blue

2 green

Total number = 20

Probability that Gina takes a red pen = number of red pens divided by the total = 10/20 = 0.5 = 50%

If she repeats the event, the second time the probability is the same: 0.5 = 50%

Probability of two events = probability of the first one multiplied by the probability of the second = 0.5 x 0.5 =0.25 = 25%

Answer:

Probability = 0.25 = 25%

User Deep Kakkar
by
2.7k points