If the ratio of the speed of the Car and speed of the truck is 4:5 and the car covers 240 km in 12 hours

If the ratio of the speed of the Car and speed of the truck is 4:5 and the car covers 240 km in 12 hours, then find the total time taken by car and truck each to cover 300 km.

a)            30 hours

b)            27 hours

c)            15 hours

d)            20 hours

Sol:

Speed of the car = 240/12 = 20 km/hr

Speed of the truck = 20*5/4 = 25 km/hr

Time taken by car to cover 300 km = 300/20 =

15 hours

Time taken by truck to cover 300 km = 300/25 =

12 hours

Total time taken = 15+12 = 27 hours