A train travels the first 15 km at a uniform speed of 30 km/h, the next 75 km

A train travels the first 15 km at a uniform speed of 30 km/h, the next 75 km at a uniform speed of 50 km/h, and the last 10 km at a uniform speed of 20 km/h. Calculate the average speed for the entire train journey.

Видео A train travels the first 15 km at a uniform speed of 30 km/h, the next 75 km автора Exuberant Ensemble