Lovely remembers that her friend had visited her after 13th but before 18th of the month, while Lovely's sister remembers that Lovely's friend had visited after 16th but before 20th. If it was Saturday on 16th of the month, then on which day of the week, Lovely's friend did visit to her?
According to Lovely : 14 15 16 17 and according to her sister : 17 18 19.
∴ The friend visited on 17th of the month. But it was Saturday on 16th. Hence the friend visited on Sunday.