Answer:
Step-by-step explanation:
The distance between two cities is 180 km.
Speed = distance/time
Time = distance /speed
This distance was covered by a car at a rate of 50 km/h
Time taken by the car to cover this distance of 180km
= 180/50 = 3.6 hours
This distance was covered by a bus at 45 km/h
Time taken by the bus to cover this distance of 180km
= 180/45 = 4 hours
This distance was covered by a truck at 40 km/h
Time taken by the truck to cover this distance of 180km
= 180/40 = 4.5 hours
This distance was covered by a bicycle at 25 km/h
Time taken by the truck to cover this distance of 180km
= 180/25 = 7.2 hours
Therefore,
speed and time are directly proportional.
Speed, s is inversely proportional to time, t
Introducing constant of variation,k
s = k/t
When s = 25, t = 7.2
25 = k/7.2
k = 7.2× 25 = 180
So
s = 180/k
