Answer:
D
Step-by-step explanation:
If you made a table and filled in the values, the rate column it would look like this:
d = r t
truck 80
car 90
So far so good. If we want the car to catch up with the truck, that means that in the end they travel the exact same amount of miles. So let's fill in the d:
d = r t
truck d 80
car d 90
Again, not too bad. If the car leaves 20 minutes later than the truck, that means that the time the truck is traveling is 20 minutes more than the car's time. So the car's time is t and the truck's time is t + 20:
d = r t
truck d 80 t+20
car d 90 t
Now because the distances are equal, we can set the rate times time for each vehicle equal to each other:
80(t + 20) = 90t
That is choice D
