1. **Problem statement:** The sum of the present ages of the father and son is 80 years. We need to find their present ages given additional information (which is incomplete in the prompt). 2. **Formula and approach:** Let the present age of the father be $F$ and the present age of the son be $S$. Given: $$F + S = 80$$ 3. Since the problem is incomplete, we cannot solve for $F$ and $S$ uniquely without more information such as the relationship between their ages at a certain time. 4. **Explanation:** Typically, problems like this provide a second condition, for example, "After $x$ years, the father will be $y$ times as old as the son," or "The difference in their ages is $d$ years." Using such a condition along with the sum, we can solve the system of equations. 5. **Conclusion:** Please provide the complete problem statement or the second condition to find the present ages of the father and son.