The transportation cost charged by a shipping company is proportional

The transportation cost charged by a shipping company is proportional to the square root of the distance and proportional to the volume of the parcel. If the distance is increased to 4 times, how much volume of the parcel can be transported with the same cost?

25%
50%
66%
75%
This question was previously asked in
UPSC CISF-AC-EXE – 2019
The correct answer is 50%.
The transportation cost (C) is proportional to the square root of the distance (D) and proportional to the volume (V). This can be written as C ∝ √D * V, or C = k * √D * V, where k is a constant.

We are given that the cost remains the same (C₁ = C₂) while the distance is increased to 4 times (D₂ = 4D₁). We need to find the new volume (V₂) in terms of the original volume (V₁).

Using the formula:
C₁ = k * √D₁ * V₁
C₂ = k * √D₂ * V₂

Since C₁ = C₂, we have:
k * √D₁ * V₁ = k * √D₂ * V₂
√D₁ * V₁ = √D₂ * V₂

Substitute D₂ = 4D₁:
√D₁ * V₁ = √(4D₁) * V₂
√D₁ * V₁ = 2√D₁ * V₂

Assuming D₁ > 0, we can divide both sides by √D₁:
V₁ = 2 * V₂

Solving for V₂:
V₂ = V₁ / 2

This means the new volume V₂ is half of the original volume V₁, which is 50%.

This type of problem involves understanding and applying direct and inverse proportionality relationships described in the problem statement. Keeping the cost constant requires adjusting the volume inversely proportionally to the square root of the distance.