so, he usually does 55 only, but this one day he did 77, 77 - 55 is 22, so he did 22 more this one day.
if we take 55 to be the 100%, what is 22 off of it in percentage anyway?
[tex]\bf \begin{array}{ccll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
55&100\\
22&p
\end{array}\implies \cfrac{55}{22}=\cfrac{100}{p}\implies p=\cfrac{22\cdot 100}{55}[/tex]
