Question

In zoe's class, 4/5 of the students have pets. of the students who have pets, 1/8 have rodents. what fraction of the students in zoe's class have pets that are rodents? qhat fraction of the students in zoe's class have pets that are not rodents?

Answer 1

Let us assume the number of student's in Zoe's class = x
Then
Number of students that have pets = 4x/5
Number of students that have rodents as pets = (1/8) * (4x/5)
                                                                          = x/10
Number of students in Zoe's class
that have pets that are not rodents = (4x/5) - (x/10)
                                                         = (8x - x)/10
                                                         = 7x/10
I hope that the procedure is clear enough for you to understand and this is the answer that you were looking for.

Answer 2

Answer with explanation:

Given : The fraction of the students have pets. of the students who have pets : $\dfrac{4}{5}$

The fraction of the students who have pets have rodents : $\dfrac{1}{8}$

The fraction of the students who have pets that are rodents :-

$\dfrac{4}{5}\times\dfrac{1}{8}=\dfrac{1}{10}$

The fraction of the students in zoe's class have pets that are not rodents :-

$\dfrac{4}{5}-\dfrac{1}{10}\\\\=\dfrac{2\times4-1}{10}\\\\=\dfrac{8-1}{10}=\dfrac{7}{10}$