A train moves with  a speed o f`30kmh^(-1)` in the first 15 minutes,with another speed
Channel: Doubtnut
Date: 2021-11-02

A train moves with  a speed o f`30kmh^(-1)` in the first 15 minutes,with another speed of `40kmh^(-1)` the next  15 minutes,and then with a speed of `60 kmh^(-1)` in the last 30 minutes. Calculate the average speed of the train of train for this journey.