To solve for \( x \) in the equation \( \frac{5}{8} = \frac{x}{24} \), we can use cross-multiplication:
\[ 5 \cdot 24 = 8 \cdot x \]
This simplifies to:
\[ 120 = 8x \]
Next, we divide both sides by 8 to isolate \( x \):
\[ x = \frac{120}{8} = 15 \]
Thus, the best answer is:
15