A bus starts from a bus station after every 30 minutes in the same direction. The speed of each bus is the same. Z is riding a bike in the opposite direction at a speed of 25 km/h. Z meets each bus in 20 minutes. What is the speed of each bus?

50 km/h

According to question ,

Distance traveled by bus in 10 min = Distance traveled by Bike in 20 minutes

Ratio of Time taken by Bus to Bike = 1  :  2

As Speed is inversely proportional to Time

So , Ratio of Speed of Bus to Bike = 2 : 1

Now , 1R = 25 km/h    ( Given)

2R = 2 × 25 = 50 km/h

So , Speed of Bus = 50 km/h