Question 550098
 My answer doesn't make any sense, could you please show me how to solve this problem. A private plane takes 8 hours less to travel 960 km than a car. If the plane travels 3 times as fast as the car, what is the speed of the plane and the car?

Make this chart

          distance   rate    time
car

plane


Let the car's speed (rate) be x
</pre>
>>...the plane travels 3 times as fast as the car...<<
<pre>
So the plane's speed (rate) is 3x

Fill these in for the rates, and 960 km for both distances:

          distance   rate    time
car          960       x

plane        960      3x

Use {{{TIME=DISTANCE/RATE}}} to fill in the TIMES:

          distance   rate    time
car          960       x     {{{960/x}}}
plane        960      3x     {{{960/(3x)}}}

Our equation comes from this:
</pre>
>>... A private plane takes 8 hours less to travel 960 km than a car...<<
<pre>

       {{{(matrix(2,1,"Plane's", time))}}} =  {{{(matrix(2,1,"Car's", time))}}}  - 8

           {{{960/(3x)}}} = {{{960/x}}}  - 8

Solve that and get x = 80 km/hr for the car and 3 times that or 240 km/hr
for the plane.