Question 621891
d stands for distance
r stands for speed 
t stands for time

so distance = speed x time
distance = 80 x 2.5
= 200 miles

You must check that the units used for the speed and the time are the same and take note of the distance per time unit to ensure that you are using the correct unit for the result. In this case both were using hours and the distance unit was mile. So the result was in miles.