Question -
Answer -
Let us assume the wellto be a solid right circular cylinder
Radius(r) of thecylinder = 3.5/2 m = 1.75 m
Depth of the well orheight of the cylinder (h) = 16 m
We know that,
Volume of the cylinder(V1) = ╧Аr2h
= ╧А ├Ч 1.752┬а├Ч16
Given,
The length of theplatform (l) = 27.5 m
Breadth of theplatform (b) =7 m
Now, let the height ofthe platform be x m
We know that,
Volume of therectangle = l*b*h
V2┬а=27.5*7*x
As the earth dug up isspread evenly to form the platform
Volumes of both, thewell and the platform should be the same.
V1┬а= V2
╧А ├Ч 1.75 ├Ч 1.75 ├Ч 16 =27.5 ├Ч 7 ├Ч x
x = 0.8 m = 80 cm
Therefore, the heightof the platform is 80 cm.