Question

A 240 mile drive to your friend's house costs $60 in gas. Your uncle lives 160 miles away. How much would it cost in gas to drive to his house?

Answer 1

$\begin{array}{ccll} miles&\ \\ \cline{1-2} 240 & 60\\ 160& x \end{array} \implies \cfrac{240}{160}~~=~~\cfrac{60}{x}\implies \cfrac{3}{2}~~=~~\cfrac{60}{x} \\\\\\ 3x=120\implies x=\cfrac{120}{3}\implies x=40$