# A number theory problem by Anik Mandal

**Number Theory**Level 3

A man who went out between 4 and 5 P.M and returned between 5 and 6 P.M. found that the hands of the clock had exactly changed spaces.When did he go out?

Note:Changed places indicates that the position of the hour hand had been taken by the minute hand and vice-versa.

If the answer is in the form of a/b minutes past 4 then find a+b.

The students who are able to solve the question must post a solution or give some hints regarding the question.