We can solve this problem by applying the rule of three:
[tex]\begin{gathered} 6\text{ lemons ----- 1 pitcher} \\ 20\text{ lemons ---- x} \end{gathered}[/tex]then, we have
[tex]x=\frac{(20)(1)}{6}[/tex]which gives
[tex]\begin{gathered} x=\frac{20}{6} \\ x=\frac{10}{3} \end{gathered}[/tex]If we convert this result into a mixed fraction form, we have
[tex]\frac{10}{3}=3\frac{1}{3}[/tex]this means that Sean maked 3 and 1/3 pitchers today.
