<PRE><B>Question 319898</B>
In a race, the top speed of one car is nine tenths of the top speed of another.
 After one half hour the faster car is 10 km ahead of the slower car.
 Find the rate of each car, assuming they started side by side.
:
Let s = faster car speed
then
.9s = speed of the slower car
:
Write a dist equation; dist = speed * time
:
Fast car dist - slower car dist = 10 km
.5s - .5(.9s) = 10
.5s - .45s = 10
.05s = 10
s = {{{10/.05}}}
s = 200 km/hr is the faster car
then
.9(200) = 180 km/hr is the slower car
:
:
Check solution by finding the dist each traveled in .5 hrs
.5(200) = 100 km
.5(180) =  90 km
------------------
dist dif: 10 km </PRE>