SOLUTION: A man travels a distance at a speed of 12 km/h and returns at 9 km/h. If the total time taken by him is 3 h 30 min, find the distance he traveled one way.

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Question 1101434: A man travels a distance at a speed of 12 km/h and returns at 9 km/h. If the total time taken by him is 3 h 30 min, find the distance he traveled one way.
Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52781) (Show Source):
You can put this solution on YOUR website!
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Let D be the unknown distance under the question, in kilometers. Then the time spent traveling at the speed 12 km/h is hours. The time spent traveling at the speed 9 km/h is hours. The total time equation is + = hours, or + = . Multiply by 36 both sides. You will get 3D + 4D = 7*18, or 7D = 7*18 ====> D = 18 kilometers. Answer. The one way distance is 18 km.

Answer by greenestamps(13200) (Show Source):
You can put this solution on YOUR website!

The other tutor gave a solution by what is probably the most common method for solving this kind of problem.

Here is a solution using a different method. Try it and see if it "works" for you....

The distances in the two directions are of course the same.

The ratio of the speeds is 4:3; since the distances are the same, the ratio of times at the two speeds is 3:4.

Dividing 3 hours 30 minutes in the ratio 3:4 means 1 hour 30 minutes at 12 km/h and 2 hours at 9 km/h.

Either of those gives 18km as the distance: 1.5*12 = 18; 2*9 = 18.