Expert: Scott A Wilson - 10/7/2009

Question
mark leaves the house for school walking at the rate of 4kph. after 2 hrs, Jane follows mark at a walking rate of 6kph. how long will Jane have to walk to overtake mark?


pls reply as soon as you can. thanks.

Answer
If he is walking at 4kph, and leaves 2 hours early, he has walked 8k already.
Since she walks 2k faster in each hour, it will take her 8/2 = 4 hours to catch him.

So Mark will have walked for 6 hours at 4kph, for a total of 6*4 = 24 k.
Jane will have walked 4 hours at 6 kph, for a total of 4*6 = 24k.

Sidenote:
Now I don't know about you, but I have a feeling if it took Mark 6 hours to get there,
I think he had somewhere else to go other than school...