On which day was Yousuf born? (His date of birth is February 29)
I. He was born between year 2009 and 2015.
II. He will complete 4 yrs on February 29, 2016.
If the data either in statement I alone or in statement II alone are sufficient to answer the question
From Statement I, as Yousuf was born on 29th February between the year 2009 and 2014, his birth year will definitely be 2012 because 2012 is the only leap year between 2009 and 2015.
Hence, from the calendar method the day on 29th Feb, 2012 can be found. Hence, Statement I alone is sufficient.
From Statement II, Yousuf will complete 4 yrs on 29th Fed, 2016. It means he was born on 29th Feb, 2012, 4 yrs back.
Now, date and year is clear. Hence, again from the calendar method the birthday can be calculated. Thus Statement II alone is also sufficient.
So, either Statement I or II alone are sufficient to answer the question.