Question

please answer it .......

Answer 1

speed of 1st car = speed of 2nd car = 30km/h

Let the speed of third car be x
Since the third car is moving in same direction
relative speed of third car = (x-30) km/h

Distance covered by third car in 4 minutes = 5km.

4 min = 1/15 hour

speed = distance/time
=> x-30= 5 divide by 1/15
=> x-30 = 15 into 5
=> x = 75+30
=> 105 km/h