Mr. Horák is 3 years older than his wife and their firstborn son is 4 years older than their second-born. All four members of the family celebrate their birthdays on the same day, and they now have a total of 81 years combined. Five years ago, the total age of the members of this family was 62 years. Determine the current age of the parents and both children.
In 5 years, a family of four should have gained $4 \cdot 5=20$ years, but they only gained $81-62=19$ years. This could only happen if the younger son was not yet born 5 years ago and contributed only 4 years to the family's total age $(3 \cdot 5+4=19)$. Therefore, the younger son is 4 years old. His older brother is 4 years older, i.e., 8 years old.

The parents together are $81-4-8=69$ years old. If the mother is $m$ years old, the father is $m+3$ years old, and it follows that $m+m+3=69$, so $m=33$.

The mother is 33 years old, the father is 36 years old, the older son is 8 years old, and the younger son is 4 years old.

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