The ratio of boys to the total number of students is 6:20; then, multiply both sides of the ratio as shown below
[tex]\begin{gathered} 6\colon20 \\ \Rightarrow5(6)\colon5(20)_{} \\ \Rightarrow30\colon100 \end{gathered}[/tex]And 30:100 is equal to 30/100=0.3=30%
Therefore, the answer is 30%