To answer this question, we can proceed as follows:
1. We have that the total of protein the human body needs daily is 50 grams.
2. A hamburger contains about 20 grams of protein.
Then, to find the asked percent, we can proceed as follows:
![\begin{gathered} (20)/(50)\cdot100\%=(2)/(5)\cdot100\%=(2\cdot100\%)/(5)=2\cdot(100\%)/(5)=2\cdot20\%=40\% \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3mjfdabn1tchhikkh9euu2iexr7s3r16mj.png)
Therefore, the hamburger has 40% of the protein we need daily.