Question

A remembers that his uncle had visited them after 13th, but before 18th of a month, while B remembers that A's uncle had visited them after 16th but before 19th. Then, on what date did A's uncle visit A and B ?

Answer 1

Given, A remembers that his uncle had visited them after 13th, but before 18th of a month.
So, according to A his uncle came at either of 14th, 15th, 16th or 17th of the month.
Now, B remembers that A's uncle had visited them after 16th but before 19th i.e., either on 17th or 18th.
From the date mentioned by both there is only one date which is common i.e., 17th.
Hence, A's uncle visited at 17th of the month.