On a straight road, a bus is 30 km ahead of a car travelling in the same direction. After 3 hours, the car is 60 km ahead of the bus. If the speed of the bus is 42 km/h, then find the speed of the car.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 72 km/h.
Given that
A bus is 30 km ahead of a car travelling in the same direction
After 3 hours, the car is 60 km ahead of the bus.
The speed of the bus = 42 km/h
Let the speed of a car be Y km/h
After 3 hours, The distance between the bus and the car = 30 + 60 = 90 km
The relative speed = (Y - 42) km/h
Formula used
Relative speed = Total distance/Total time
Calculation
Y - 42 = 90/3
Y = 30 + 42 = 72 km/h