Rajasthan Police Constable Model Paper 7

We know that,
⇒ Relative speed = Total distance/Total time
⇒ Relative speed = (60 + 40)/20 = 5 m/s
⇒ 5 m/s = 5 × 18/5 = 18 km/h
Now,
⇒ Relative speed = Speed of school Bus - Speed of Ambulance
⇒ 18 = 30 - Speed of Ambulance
⇒ Speed of Ambulance = 12 km/h
∴ Speed of Ambulance is 12 km/h