HOW TO GET THOSE SORT OF QUESTIONS OF CLOCK LIKE A MAN STARTS BETWEEN 4-5PM AND COMES BACK BETWEEN 8-9 PM AND HE OBSERVES THAT HOUR HAND AND MINUTE HAND HAVE INTERCHAGED...

Hi,
You can simply use the concept of the angle traversed by the hand in a minute or in a hour. This will give you some equations and you can solve those equations to arrive at the answer. To get a better understanding, please post a question, we will try and answer it in detail.