In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data
6 boxes of spaghetti ==> 20 people
50 people
boxes = ?
Step 02:
[tex]\text{boxes = 50 people }\cdot\text{ }\frac{6\text{ boxes}}{20\text{ people}}\text{ = }15\text{ boxes}[/tex]The answer is:
Thiago should make 15 boxes .