Question

The distance bewteen Harry and Kate is 2500 meters. Kate and Harry start walking toward one another and Kate' dog start running back and forth between Harry and Kate at a speed of 120 meters per minute. Harry walks at the speed of 40 meters per minute while Kate walks at the speed of 60 meters per minute. What distsnce will the dog have travelled when Harry and Kate meet each other?

Answer 1

Well, Kate and Harry together are walking 100 meters per minute. Which means it will take them 25 minutes to reach each other (I think). 

If the dog is running 120 meters per minute: 120 x 25 = 3,000.

The dog will run 3,000 meters (if he runs constantly to and from the spot that Kate and and Harry started).