To solve the inequality \( \frac{4}{5}d \leq 24 \), follow these steps:
1. Multiply both sides of the inequality by \( \frac{5}{4} \) to isolate \( d \):
\[
d \leq 24 \times \frac{5}{4}
\]
2. Calculate \( 24 \times \frac{5}{4} \):
\[
24 \times \frac{5}{4} = 24 \div 4 \times 5 = 6 \times 5 = 30
\]
Therefore, the solution to the inequality is:
\[
d \leq 30
\]