Question

a car cover certain distance at a speed of 45 km/hr in 4 hrs what should be speed to cover the same distance in 3 hrs? if the speed of the car is 40 km/hr then find the time required to cover that distance

Answer 1

Let distance be x
45=x/4
X=45*4
= 180 km
If time 3 hr then
Let speed x for same distance 180km
X =180/3
=60km/hr
Also ,
Speed 40km/hr
Let time be x
40=180/x
X=180/40
=9/2
=4.5 hr

Answer 2

speed = 45km/hr
time = 4 hrs
distance = speed*time
               = 45*4 = 180km
when diatance is 180 km and time is 3hrs
then, speed = distance/time 
                 = 180/3 = 60km/hr
when speed is 40km/hr and distance is 180km 
then, time = distance/speed
                 = 180/40 = 4.5hrs
hope it will help u