Question 990740
The truck travels for more time and travels slower than the car.  Car and truck meet when they each go the same distance from departure.  Half hour difference between 7AM and 7:30AM.


<pre>
VEHICLE     SPEED     TIME     DISTANCE
Truck       20        t+1/2     d
Car         80         t        d
</pre>


RT=D relates rate, time, distance; for uniform travel rates.


{{{system(20(t+1/2)=d,80t=d)}}}


{{{highlight(20(t+1/2)=80t)}}}
Solve for t.