A science class has

3

girls and

7

boys in the seventh grade and

2

girls and

2

boys in the eighth grade. The teacher randomly selects a seventh grader and an eighth grader from the class for a competition. What is the probability that the students she selects are both boys?

Question

Mathematics

Darrell Young

9 November, 10:55

A science class has

3

girls and

7

boys in the seventh grade and

2

girls and

2

boys in the eighth grade. The teacher randomly selects a seventh grader and an eighth grader from the class for a competition. What is the probability that the students she selects are both boys?

+5

Answers (1)

Know the Answer?

Gemma Tate · Answer 1

The probability that the teacher selects both boys from a seventh grader and eighth grader.

first calculate the probility that it is boy in each grade

7th

x = 7 / (7 + 3) = 7 / 10

8th

y = 2 / (2 + 2) = 1 / 2

so the probability

P = (7 / 10) (1 / 2)

P = 0.35

A science class has3girls and7boys in the seventh grade and2girls and2boys in the eighth grade. The teacher randomly selects a seventh grader and an eighth grader from the class for a competition. What is the probability that the students she selects are both boys?

A science class has

3

girls and

7

boys in the seventh grade and

2

girls and

2

boys in the eighth grade. The teacher randomly selects a seventh grader and an eighth grader from the class for a competition. What is the probability that the students she selects are both boys?