Answer:
casey has the faster rate
Explanation:
first multiply jessicas race distance and time by 2 
30 * 2
= 60 
5 * 2 
= 10
we did that so both jessicas time and caseys time was the same, making it easier to solve ( also by this point we already know who has the faster rate )
now we are going to divide both of their times and distances by 5 
casey
10/5 
= 2
45/5
= 9
jessica 
10/5
= 2
60/5
12
the step is to divide their times/distances once again but this time by 2 
casey 
2/1
= 1
9/2
= 4.5
jessica 
2/1
= 1
12/2
= 6 
and our answer is 4.5 or casey !
4.5 > 6
hope this helps you! :)