Question 297576
This is a rate/time/distance problem so we will use the following formula:
Rate x Time = Distance

Establish your terms:
Let r = the rate of speed of car A
Let 2r = the rate of speed of car B (remember, one car is going twice as fast as the other)
Using the formula rate x time = distance
Let 5r = the distance car A travels after 5 hours 
Let 5(2r) = 10r = the distance car B travels after 5 hours

Since car B is the faster car it will have travelled farther after 5 hours so:

Distance car B travels - distance car A travels = 275
Using our terms from above:
{{{10r - 5r = 275}}}
{{{5r = 275}}}
{{{r = 55 kph}}} 
and 
{{{2r = 110 kph}}}
Car A is travelling at 55 kph and car B is tavelling at 110 kph.