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There are 7 students in a class: 5 boys and 2 girls.

If the teacher picks a group of 3 at random, what is the probability that everyone in the group is a boy?

1 Answer

2 votes

Answer:

2/7

Explanation:

1. You have to find the probability that a boy will be picked three diferent times

2. # of boys/total #of students

3. 5/7

4. Now that one boy is picked, there is only a total of 6 students left and only four boys so your proportions change

5. 4/6

6. Now there is only 5 students left and 3 boys left

7. 3/5

8. Multiply these proportions together

9. 5/7 times 4/6 times 3/5 = 2/7

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