A classical mechanics problem by Sharad Roy
A car moves from Village A to Village B with a speed of 30 kmph. After it reaches village B, it takes a U-turn and starts heading to village A. It travels half of its time with a speed of 25 kmph and other half with a speed of 20 kmph. Find the average speed of the car during the whole journey?
Note: Speed of car is uniform when it travels from village A to B, while when it is heading back to Village A from B its speed's are different i.e. 20 kmph and 25 kmph. You need to find average speed of car during the whole journey.