Question 970958
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The other tutor provided a formal algebraic solution, using a standard method.<br>
Here is a different, less formal solution.<br>
Equal distances at different speeds in the ratio A:B means the times spent at the two speeds are in the ratio B:A.<br>
In this problem, the two speeds are in the ratio 60:40 = 3:2, so the times spent at the two speeds are in the ratio 2:3.<br>
The total time was 10 minutes; splitting that in the ratio 2:3 means the trip was 4 minutes (1/15 hour) at 60 km/h and 6 minutes (1/10 hour) at 40km/h.<br>
Distance is rate times time, so the distance traveled at 60 km/h was {{{(1/15)(6)=4}}} km and the distance traveled at 40 km/h was {{{(1/10)(40)=4}}} km.<br>
So the total distance was 4+4 = 8 km.<br>
ANSWER: 8 km<br>