Solution:Concept- Use the fundamental description of volume. As we can see, earth that has been dug is also referred to if it is 7 meters in diameter and 30 meters deep, but when we look at it geometrically, it has a cylinder shape with a specific height and diameter.
The cylindrical well's diameter and depth are 30m and 7 meters.
For the cubical platform, the volume of dirt used to prepare the platform is equal to the following dimensions: length l = 30 m, breadth = 10 m, and height = X m.
Hence, the correct answer is option 1) 3.85m