a science class have five girls and three boys in 7th grade at two girls and two boys in the 8th grade the teacher randomly selects a 7th grader and an 8th grader from the class for competition what is the possibility that the students she selected are both girls

Possibility that the students selected are both girls = 31.25%

Step-by-step explanation:

It is given that

A science class have 5 girls and 3 boys in 7th grade

And 2 girls and 2 boys in the 8th grade

In 7th grade total students = 8

In 8th grade total students = 4

Total possibilities = 8 x 4 = 32

The teacher randomly selects a 7th grade and an 8th grade

The number ways a girl selected from 7th grade = 5c1 = 5

The number ways a girl selected from 8th grade = 2c1 = 2

Total possibilities = 5 x 2 = 10

Probability that the students selected are both girls = 10 / 32 = 31.25%