Study the following details carefully and answer the question that follows.

Six colleagues—K, J, D, W, H, and Z—were born in six different months: February, March, May, June, August, and September, of six distinct years: 2004, 2007, 2010, 2011, 2014, and 2015. Except for the chronological order of the years, the remaining details are not necessarily in the sequence presented.

K was born in a year with an even number but immediately after H. Two colleagues were born between K and the one who was born in February. The colleague born in September is 5 years older than Z, who was born in a month containing an odd number of days. J and D were born one after the other with no births in between, and both were born before the year 2010. The number of colleagues born after the one born in June is equal to the number of colleagues born before W. J was born neither in a month with 31 days nor in August.

What is the difference between the years in which W was born and the one who was born in August?

Correct Answer: Can’t be determined

Step-by-Step Explanation:

Step 1: Arrange the years chronologically and identify the given details
The six birth years in chronological order are:
1. 2004
2. 2007
3. 2010
4. 2011
5. 2014
6. 2015

The six birth months and their days are:
• February (28/29 days)
• March (31 days)
• May (31 days)
• June (30 days)
• August (31 days)
• September (30 days)

Step 2: Determine September and Z's birth year
We are given that the colleague born in September is 5 years older than Z. This means the colleague born in September was born 5 years prior to Z:

$\text{Year(Z)}-\text{Year(September)}=5$

Checking pairs of years with a difference of 5 years:

$2015-2010=5$

This is the only valid pair. Therefore:
• The colleague born in September was born in 2010.
• Z was born in 2015 in a month containing 31 days.

Step 3: Determine the positions of J, D, H, K, and W
1. J and D were born one after the other before 2010. Thus, J and D occupy 2004 and 2007.
2. K was born in an even year immediately after H. The available even years are 2004, 2010, and 2014.
• K cannot be in 2004 (no preceding year).
• K cannot be in 2010 because H would have to be in 2007, which is already occupied by J/D.
• Therefore, K was born in 2014, and H was born in 2011.
3. The remaining year 2010 must belong to W. Since 2010 is the September birth year, W was born in September 2010.

Step 4: Determine the birth months for June and February
1. The number of colleagues born before W (2010) is 2 (2004 and 2007). Therefore, 2 colleagues were born after the one born in June, placing June in 2011 (H was born in June 2011).
2. Two colleagues were born between K (2014) and the person born in February. Counting back 2 positions from 2014 brings us to 2007. Thus, the person born in 2007 was born in February.

Step 5: Assign exact positions to J and D
The months assigned so far are February (2007), September (2010), and June (2011).
The remaining months are March, May, and August—all of which have 31 days.
Since J was not born in a 31-day month, J could not be born in 2004 (which must take a 31-day month).
Therefore, J was born in February 2007, and D was born in 2004.

Step 6: Summary of deductions
• 2004 (D): March / May / August
• 2007 (J): February
• 2010 (W): September
• 2011 (H): June
• 2014 (K): March / May / August
• 2015 (Z): March / May / August

Conclusion:
The remaining 31-day months (March, May, and August) cannot be uniquely fixed to 2004, 2014, or 2015 based on the given clues. Because the birth year of the colleague born in August could be 2004, 2014, or 2015, the exact difference between the birth year of W (2010) and the birth year of the colleague born in August cannot be determined.