I'll be refering to the answer given by El'enidia Starman, just a bit more changes and additional explaination.
El'enidia Starman's Answer: Well, first off, let's list all the possible combination of ages (and their sum):
1,1,36;381,1,36;38 1,2,18;211,2,18;21 1,3,12;161,3,12;16 1,4,9;141,4,9;14 1,6,6;131,6,6;13 2,2,9;132,2,9;13 2,3,6;112,3,6;11 3,3,4;103,3,4;10 I'm not sure what to make of the building one, but note the specific wording in the third clue: "older". The only reason you would say "older" when referring to THREE people (you would typically use "oldest") means that two of them must be twins. So, you now have three possibilities left:
1,1,36;381,1,36;38 2,2,9;132,2,9;13 3,3,4;103,3,4;10 I don't know how to use the building clue to pare the choices down to one.
That help?
EDIT: Apparently, "older" should be "oldest". In that case, the solution could be any of them but one. In addition, the missing piece is that if the person solving the puzzle knows the number of windows in the building but still cant figure it out, then the two possibilities are:
1,6,6;131,6,6;13 2,2,9;132,2,9;13 At this point, the remark about "oldest" rules out the first one and leaves only 2,2,92,2,9 as the correct answer.
Additions: Now some of you must be wondering how did he end up with one correct answer from two, so let me simplify.
Firstly, 1,1,36;381,1,36;38 1,2,18;211,2,18;21 1,3,12;161,3,12;16 1,4,9;141,4,9;14 1,6,6;131,6,6;13 2,2,9;132,2,9;13 2,3,6;112,3,6;11 3,3,4;103,3,4;10 In the above List, when the second clue is provided, the solver would know that the window has a certain number of windows. This number may be 38, 21, 16, 14, 13, 13, 11, 10 now if the number of windows was 38, 21, 16, 14, 11 or 10, then the solver would have come to know the ages as there are no other combination with the same number of windows. But the solver says, that he is still not able to find the answer. This means that the number of windows is 13 and there are two combinations with the sum of ages as 13 which are:
1,6,6;131,6,6;13 2,2,9;132,2,9;13
Now the third clue says that the oldest son has blue eyes. Now, in the first age combination 1,6,6 there are two oldest son's ages which is 6. Thus, there is no oldest son in this case. However, in the second combination there is only one oldest son with age 9. That is why the solver was able to conclude that 2,2,9 is the correct age combination.
Hope I could clarify the doubts if any.