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?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e 50 km/h
Explanation :
Let the speed of each bus be X km/hr.
Distance covered by the bus in 30 minutes = X (30/60) = X/2 km.
Now, Z is travelling in opposite direction, so the relative speed = (X + 25) km/hr
Now, (X + 25) × 20/60 = X/2
⇒ (X + 25) × 1/3 = X/2
⇒ X + 25 = 3X/2
⇒ 3X/2 - X = 25
⇒ X/2 = 25
⇒ X = 50.
Hence the required value of the speed of each bus is 50 km/hr.