Question

a car runs at a speed of 65 kmh to reach its destination in 45 minutes.What should be its speed for it to reach the destination in 36 minutes?​

Answer 1

Speed =65km/h =65×5/18=325/18 m/sec

Time=45mins=45×60 =2700sec

Distance =Speed ×Time

=325×2700/18 =48750 m=48.75km

Now S=D/T

Time=36mins=36/60 hours

S=48.75/36/60=81.25 kmph

Answer 2

Case 1 :

Speed of the car = 65 Km/h

Time taken to reach the destination = 45 minutes = 45/60 = 0.75 Hours (1 minute = 1/60 Hour and 45 minutes = 1/60 * 45 = 0.75 Hour)

We know that,

Speed = Distance covered/Time taken

65 = Distance covered/0.75

65 * 0.75 = Distance covered

Distance covered = 48.75 Km

Case 2 :

Distance covered = 48.75 Km

Time taken = 36 minutes = 36/60 = 0.6 Hours

Speed = Distance covered/Time taken

Speed = 48.75/0.6

Speed = 4875/60

Speed = 81.25 Km/h

81.25 Km/h should be its speed to reach the destination in 36 minutes.