If a car's average speed is 59 kilometers in 2.6 hours?

If what you want is the total distance traveled, you need to multiply the average speed by the time.Please note that "59 kilometers" is not a speed; perhaps you mean "59 kilometers per hour".

If, on the other hand, "59 kilometers" is the TOTAL DISTANCE, and you want the average speed, you need to divide the total distance by the time.