Question

You are driving home from school steadily at 95 km/h for 130 km. During raining, you begin to
slow down to 65 km/h. You arrive home after driving for 3 hours and 20 minutes. Calculate your
total distance travelled from home to school.

Answer 1

We have 2 journeys , one to school and one to home.
We already have the distance travelled in the first journey .
To find the distance of the second one , we need to find out the time .

Because ,
D= Time x speed
Since have the distance of the first journey , we can find the the time of the second journey .

Using the formula:
Time= D/S

To find the total time :

First:
Convert 20 minutes to hours : 20/60= 0.33 hrs
And add it to 3 (3hrs) = 3+0.33= 3.33hrs

This is our total time .


Second:
To find the time of the first journey , we divide:
130/95= 1.36hrs
(D/S)=T

Since we need the time of the second half, we subtract the time of the first half from the total time travelled:
3.33-1.36= 1.97hrs

And that’s how we found out the time of the second journey (again to find distance).

Now , the last step is to workout the distance travelled at the second journey.
We have the time = 1.97 hrs and the speed = 65 km/h
D=T x S
1.97 x 65= 128.05 km

And that’s your answer.