Answer
$x=24$
Work Step by Step
We use the method of cross multiplying, which states that if $\frac{a}{b} = \frac{c}{d}$, then $ad = bc$. This result can be achieved by multiplying both sides by $cd$.
$\frac{5}{3} = \frac{40}{x} \rightarrow 5x = 120 \rightarrow x = 24$
