Arithmetic Aptitude :: Average
8. A car averages 55 mph for the first 4 hours of a trip and averages 70 mph for each additional hour. The average speed for the entire trip was 60 mph. How many hours long is the trip?
Lets assume additional hours = x hrs.
So total No. hours in journey = (4+x)
Therefore, Total No. of hrs. in Journey = (x+4) = 6 hrs.