Verified Answer :

The ratio of 25 cars to 15 cars in lowest terms would be, 5/3.

25 : 15
Divide both by 5, since they are divisible by 5
\(\frac{25}{5} : \frac{15}{5}\)
25 divided by 5 is 5 ; 15 divided by 5 is 3 so
5 : 3
5 : 3 is lowest terms since nothing can be divided again, 5 is in lowest terms, 3 is in lowest terms.