Mrs. Jones surveys her class of 20 students about their siblings. In the class, 15 have a brother, 16 have a sister, and 12 have both a brother and a sister. What is the probability that a student has a brother OR a sister?

Question

Mathematics

Deangelo Dalton

23 December, 09:43

Mrs. Jones surveys her class of 20 students about their siblings. In the class, 15 have a brother, 16 have a sister, and 12 have both a brother and a sister. What is the probability that a student has a brother OR a sister?

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Answers (2)

Know the Answer?

Marisol Johnston · Answer 1

About 10 % of people might have a brother or sister

Kareem Boyer · Answer 2

P (Brother or Sister) =.75 +.82 -.65 P (Brother or Sister) =.92 = 92% The reason you subtract the. 65 is that scenario does not fit the rule. The rule is the probability of having a brother OR a sister. The. 65 represents the kids who have both not either.