Let’s solve this step by step:

1. First equation:

   $$\text{Shoes}+\text{Shoes}+\text{Shoes}=30$$

   This implies each pair of shoes is $10$:

   $$10+10+10=30$$

2. Second equation:

   $$\text{Boy}+\text{Boy}+\text{Shoes}=20$$

   Since the shoes are $10$, we have:

   $$2\times \text{Boy}+10=20$$

   Solving for the boy:

   $$2\times \text{Boy}=10\Rightarrow \text{Boy}=5$$

3. Third equation:

   $$\text{Burger}+\text{Burger}+\text{Boy}=13$$

   We know the boy is $5$, so:

   $$2\times \text{Burger}+5=13$$

   Solving for the burger:

   $$2\times \text{Burger}=8\Rightarrow \text{Burger}=4$$

4. Final equation:

   $$\text{Shoe}+(\text{Boy with two small burgers})\times \text{Burger}=?$$
   • A single shoe is half of a pair, so it’s $5$.
   • The boy with two small burgers should represent $5+2=7$.
   • The burger is $4$.

   Now, substitute into the equation:

   $$5+(7\times 4)=5+28=33$$

Answer: 33