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There is a bag filled with 3 blue and 4 red marbles.

A marble is taken at random from the bag, the colour is noted and then it is replaced.
Another marble is taken at random.
What is the probability of getting 2 blues?

There is a bag filled with 3 blue and 4 red marbles. A marble is taken at random from-example-1
User Yasheka
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2 Answers

1 vote

3 of 7 and the chances of getting red is 4 of 7

Step-by-step explanation:

User Johan Stuyts
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5.0k points
2 votes

Answer: 9/49

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Step-by-step explanation:

The fraction 3/7 represents the probability of picking a blue marble since there are 3 blues out of 3+4 = 7 total.

Because the first marble is put back, this means the probability of picking blue does not change. So 3/7 is the probability of picking another blue marble.

Overall, we have (3/7)*(3/7) = 9/49 as the probability of picking two blues in a row.

User Sertug
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4.4k points