Answer
$\frac{5}{3}$
Work Step by Step
Since $\lim\limits_{x \to 0}$ $\frac{sin x}{x}$ = 1 and $\lim\limits_{x \to 0}$ $\frac{sin 5x}{3x}$ has the same exponential power on both top and bottom,
$\lim\limits_{x \to 0}$ $\frac{sin 5x}{3x}$ = $\frac{5}{3}$