There are 70 high school students attending the annual Johnson High School junior and senior dance. Of the 70 students attending , 30 of the are girls, 24 of the students are seniors, and 6 of the girls are seniors.

In Area 1, place the number of students who are girls and seniors.
In Area 2, place the number of girls who are not seniors.
In Area 3, place the number of seniors who are not girls.
In Area 4, place the number of students who are boy juniors.
Q: Given that a student is a senior, what is the probability that the student is a girl?

Respuesta :

1. The number of students who are girls and seniors is 6.

2.
The number of girls who are not seniors is 30 - 6 = 24.

3.
The number of seniors who are not girls is 24 - 6 = 18.

4.
The number of students who are boy juniors (70 - 24) - (30 - 6) = 46 - 24 = 22.

P(G\S) = Number of girl seniors / number of seniors = 6 / 24 = 0.25 = 25%.