Question

while walking outside on a field trip 85%, or 17, of the students in a class wore jackets. Find the number of students in a tire class?

Answer 1

say "x" is all students, namely the 100%.

so we know that 17 is the 85%, what is the 100%?

`\bf \begin{array}{ccll} amount&\%\\ \cline{1-2} 17&85\\ x&100 \end{array}\implies \cfrac{17}{x}=\cfrac{85}{100}\implies \cfrac{17}{x}=\cfrac{17}{20} \\\\\\ \cfrac{17}{17}=\cfrac{x}{20}\implies 1=\cfrac{x}{20}\implies 20=x`