The longitudinal sections of a runway have gradients as shown in the table.
\begin{array}{|c|c|}
\hline \text{End to end for sections of runway (m)} & \text{Gradient} (\%) \\
\hline 0 \text{to} 200 & +1.0 \\
\hline 200 \text{to} 600 & -1.0 \\
\hline 600 \text{to} 1200 & +0.8 \\
\hline 1200 \text{to} 1600 & +0.2 \\
\hline 1600 \text{to} 2000 & -0.5 \\
\hline
\end{array}
Consider the reduced level $\text{(RL)}$ at the starting point of the runway as $100 \mathrm{~m}$.
The effective gradient of the runway is
- $0.02 \%$
- $0.35 \%$
- $0.28 \%$
- $0.18 \%$