In a square land of 200 m × 200 m size, saplings are to be planted such that the distance between the saplings as well as the distance of saplings from the boundary of the land are not less than 20 m. What is the maximum number of saplings that can be planted in the land?

Correct option is B

Given:

• Land size = 200 m × 200 m (square)
• Minimum distance between saplings = 20 m
• Minimum distance from boundary to saplings = 20 m
• We are to find the maximum number of saplings that can be planted under these constraints.

Solution:

To maximize the number of saplings:

• We arrange them in a grid (rows and columns)
• The first sapling is planted at 20 m from the boundary
• Subsequent saplings are placed at 20 m intervals

So, effective usable length/width for placing saplings = 

​$$\text{Usable range} = 20\, \text{m to } 180\, \text{m} \\\Rightarrow \text{Total spacing} = 180 - 20 = 160\, \text{m} \\\Rightarrow \text{Number of saplings along one side} = \frac{160}{20} + 1 = 8 + 1 = 9 \\$$

Total saplings = 9 × 9 = 81
Final Answer: (B) 81
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