Taking a walk
Nola walks the mountain path from her home to lilavati house. She leaves her house at 9am on monday morning at stays the night. She walks back home along the same path at 9am on tuesday. Is there a point on the path which she passes at the same time on both days? why? You may not assume any information othere than whats given here.
The answer is yes
Why? (I'm not assuming the following, but I do need it to explain) Let's say it's the same day where two people, A and B, are facing each other going along the same path and A winds up where B's at and B winds up where A is at. At some point along the way, A and B pass each other (after 9 AM which is a given in the problem).
Based on the above explanation it's evident that Nola must pass the same point (after 9 AM) at the same time on Monday and Tuesday.
This makes sense. I was whinking the midpoint. but cand assume the path has a midpoint. In your explanation isnt it possible for A and B to meet at a point which isnt the midpoint?
Edit: what i said above doesnt matter :P thanks!
Sure...they'll ONLY meet at midpoint if their speeds are the same.
Originally Posted by Niall101
How did you come up with this puzzle?