Answer
$\text{E.}$ $\frac{x}{3}=24$
Work Step by Step
The phrase "The quotient of $3$ and a number" means that we divide a variable, $x$, by the number $3$, giving us $\frac{x}{3}$. The phrase "is 24" means "is equal to 24," which we express with $=24$. When we combine these two parts, we get $\frac{x}{3}=24$, which is choice $\text{E.}$
