Stillwater Junior High divides students into teams taught by a group of teachers. The table shows the number of students

Question

in each team.

team number of students
acers 78
blazers 80
outbacks 83
quasars 77
voyagers 82
total 400

The principal uses a computer to randomly select the name of a student from all the students in the school. With the
computer program, it is possible to draw the name of the same student twice. If the principal selects the name of a
student from the Acers on the first try, what is the probability she will draw the name of a student from the Acers on the
second try?

Answer 1

The probability of drawing a student from the Acers on the first try is 78/400.

Assuming the principal does not replace the student back into the pool after the first draw, the number of students left in the Acers team is now 77 and the total number of students left in the school is now 399.

Therefore, the probability of drawing a student from the Acers team on the second try is 77/399.

So, the probability she will draw the name of a student from the Acers on the second try, given that she drew a student from the Acers on the first try, is

(78/400) * (77/399) = 0.0487 or 4.87%.