Thanks!
Problem 2:
36 can be fatorated into 2*2*3*3 = 36. Therefore, the possibilities are:
4, 3, 3 , day 10
6, 2, 3, day 11
9, 2, 2 day 13
There is when my English starts to itch my head on something: if that son is the "eldest" and not the "elder", does that mean he has another son who is...