The car drove the first half of the route at 42 km / h, and the second at 102 km / h.

The car drove the first half of the route at 42 km / h, and the second at 102 km / h. Find the average speed of the car along the way.

If the car was moving on the first section of the path with one speed (without acceleration), and on the second – with another, therefore, its average speed is equal to half of their sum.
Thus, the average speed of a car that has driven half of the way at a speed of 42 km / h, and the second at a speed of 102 km / h will be equal to:
(102 + 42) / 2 = 144/2 = 72 km / h.
Answer: The average vehicle speed is 72 km / h.