Question 91752
There are different ways to solve this problem. 

In my solution I let T to represent the time.

we set up the equation based on the fact that one car is 30km/hr faster than the other.


So  {{{320/T - 200/T}}} = 30

then {{{120/T}}} = 30.  so  T = 4 hours.

The speed for faster car is {{{320/4}}} = 80km/hr
The speed for slower car is {{{200/4}}} = 50km/hr