What is the date of birth of Ratna? (Assume that the memories of Vani and Sapna are correct.)
I. Vani remembers that Ratna’s date of birth is between 17th June and 21st June.
II. Sapna says that Ratna’s date of birth is after 19th June but before 23rd June.

Explanation

From statement (1), we conclude that the possible answers are 18th June, 19th June and 20th June. From statement (2), we conclude that 18th June and 19th June are ruled out. So, 20th June must be the answer. Hence, the question can be answered using both the statements and, therefore, the answer is C.