Answer:
5 animals in one hour
Explanation:
Ratios are fractions set equal to each other, like this:

We have one side of the ratio:

If we set 7 hours equal to 1 hour, we'll end up with:

If we cross multiply we end up with:
35*1 = ?*7
or
35 = 7x
When we divide both sides:
5 = x
So the vet cared for 5 animals in one hour.