Two cars start at the same location and travel in the same direction at average speeds of 40 miles per hour and 55 miles per hour. How much time must elapse before the two cars are 10 miles apart?

Question

anonymous · Answer

we got a distance = rate times time problem
first rate is 40 and distance will be $40t$ second rate is 55 and distance will be $55t$ and you want to know when the second one is ten more than the first, so set 
$$40t+10=55t$$ and solve for $t$