Question

The driver of an ambulance sees a school bus 40 m ahead of him after 20 seconds, the school bus is 60 meter behind. If the speed of the ambulance is 30 km/h, what is the speed of the school bus?
A.10 kmph
B.12 kmph
C.15 kmph
D.22 kmph

Answer 1

Hi Mate
Relative Speed,
= (Total distance)/total time 
= (60+40) /20 
= 5 m/s = (5*18)/5 = 18 kmph
Relative Speed = (speed of ambulance - speed of school bus)
Speed of school bus = speed of ambulance - relative speed.
= 30-18 = 12 kmph.