Question

Jack drove to the train station and back. It

took two hours less time to get there than

it did to get back. The average speed on

the trip there was 40 km/h. The average

speed on the way back was 24 km/h. How

many hours did the trip there take?

Answer 1

8hours

Explanation:

let the time taken to get back be x

so that the time needed to go is (x-2)

we know that speed= distance/time

therefore the speed for the return is 24 km/h.

distance (return)= 24*x

distance (return)=24x

therefore the speed to the station is 40 km/h.

distance (return)= 40*(x-2)

distance (return)=40x-80

We know that the distance is the same

24x=40x-80

24x-40x=-80

16x=80

divide both sides by 16

x=5

the time taken to get back is x=5hours

the time taken to is x-2=(5-2)= 3hours

the total trip takes 3+5= 8hours