he has "x" total, so if "x" is the 100%, and 27 is the 60%, what's "x"?
well [tex]\bf \begin{array}{ccllll}
amount&\%\\
\text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\
x&100\\
27&60
\end{array}\implies \cfrac{x}{27}=\cfrac{100}{60}[/tex]
solve for "x".