Step 1: Understanding the Concept:
This question tests knowledge of planting systems and calculation of plant population.
Step 2: Key Formula or Approach:
For Triangular system of planting, the formula for calculating the number of plants per hectare is:
\[
\text{Number of plants per hectare} = \frac{10000}{\text{Area per plant}}
\]
In triangular planting, the area per plant is given by:
\[
\text{Area per plant} = \frac{(\text{Spacing})^2}{0.866}
\]
where 0.866 is the factor for equilateral triangle arrangement.
Step 3: Detailed Explanation:
Given spacing = \(5m \times 5m\)
First, calculate the area occupied by each plant in triangular system:
\[
\text{Area per plant} = \frac{5 \times 5}{0.866} = \frac{25}{0.866} = 28.87 \text{ sq m}
\]
Now, calculate the number of plants per hectare:
\[
\text{Number of plants} = \frac{10000}{28.87} = 346.3
\]
Wait, this gives approximately 346 plants.
But the standard formula for triangular planting is:
\[
\text{Plants per hectare} = \frac{10000}{S^2} \times 1.154
\]
where \(S\) is the spacing in meters.
\[
\text{Plants per hectare} = \frac{10000}{25} \times 1.154 = 400 \times 1.154 = 461.6
\]
Thus, approximately 461 plants per hectare.
Option (B) 461 is the correct answer.
Step 4: Final Answer:
Thus, the number of acid lime plants under triangular system is 461, which corresponds to option (B).
[0.5cm]