Suppose that Lucy will be $x$ years old $5$ years later, Cathy will be $$(x+13)$$ years old. $x+(x+13)=51$, so $x=19$. Thus, Cathy will be $13+19=32$ years old $5$ years later. 
When Kerr was born, Barry was $13$ years old. The sum of their ages $5$ years later will be $51$. How old will be Barry $5$ years later? 
1. $$11$$ 
2. $$15$$ 
3. $$19$$ 
4. $$33$$ 
5. $$34$$ 