Please comment your solutions, questions and remarks..
The posts have been a bit advanced lately. Let us lighten the atmosphere by this riddle which admits a simple solution, though mathematicians tend to use calculus in solving it:
An Indian monk lives near a mountain. He wakes up in the morning at 6 a.m. and goes up the mountain. The journey takes six hours and at noon he is on the top. Then he meditates 18 hours and when it is 6 a.m. again, he goes down following exactly the same route as on the way up and it also takes six hours. Show that there is a point on the route which is passed by the monk at exactly the same time on both days.
This image is licensed under the Creative Commons Attribution-ShareAlike 2.5 License. I took from Wikipedia.