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.

72 km/h

Let the speed of the car be C km/h

According to the question,

Relative speed = C - 42 km/h

Distance = 30 + 60 = 90 km

Now Speed of the car will be

 C - 42 =  \(\frac{90}{3}\)

C - 42 = 30

C = 30 + 42 = 72 km/h

So ,  The speed of the car is 72 km/h