Question

A 21 m deep well with diameter 6 m is dug and the earth from digging is evenly spread to form a platform 27 m ✕ 11 m. Find the height of the platform.[Use `pi=22/7`]

Answer 1

Depth of the well, H = 21 m

Radius of the well, R = `6/2` m = 3 m

Length of the platform, l = 27 m

Breadth of the platform, b = 11 m

Let the height of platform be h.

We know

Volume of earth dug from the well = Volume of earth used to form the platform

∴ πR²H=l×b×h

⇒`22/7`×3²×21=27×11×h

⇒ h = 2 m

Hence, the height of the platform is 2 m.