Austin went to the bookstore traveling 10 mph and returned home traveling 20 mph. If the total trip took 6 hours, how long did Austin travel at each speed?
We can write an equation that says x + 2x = 6. When we solve for x we get x=2. Then we can plug x into the equation x + 2x = 6 or 2 + 4 = 6. So he drove for 2 hours at 10 mph and 4 hours at 20 mph.
