Question

31% of what is 37 miles?

Answer 1

Let's say is "x", so "x" is the 100%, and we know that 37 is the 31%, so, what's "x"?

$\bf \begin{array}{ccll} amount&\%\\ \text{\textemdash\textemdash\textemdash}&\text{\textemdash\textemdash\textemdash}\\ 37&31\\ x&100 \end{array}\implies \cfrac{37}{x}=\cfrac{31}{100}\implies \cfrac{37\cdot 100}{31}=x$