If a student is selected at random from Learngood Elementary, what is the probability that the student will be a boy?

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Magoosh

If a student is selected at random from Leargood Elementary, what is the probability that the student will be a boy?

1) There are 480 students at Learngood
2) At Learngood, the ratio of boys to girls is 7:5

OA B

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AAPL wrote:
Sat Mar 19, 2022 6:37 am
Magoosh

If a student is selected at random from Leargood Elementary, what is the probability that the student will be a boy?

1) There are 480 students at Learngood
2) At Learngood, the ratio of boys to girls is 7:5

OA B
Target question: What is the probability that the (selected) student will be a boy?

Statement 1: There are 480 students at Learngood.
Since we have no information about the number of boys at the school, statement 1 is NOT SUFFICIENT

Statement 2: At Learngood, the ratio of boys to girls is 7:5
This tells us that, for every 12 children at the school, 7 are boys, and 5 are girls.
In other words, 7/12 of the students at the school are boys, which means P(selected student is a boy) = 7/12
Since we can answer the target question with certainty, statement 2 is SUFFICIENT

Answer: B

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