Question

a well is dug whose diameter is 7 M and 20 m depth
find the quantity of earth taken out to construct the well

Answer 1

Answer:

Step-by-step explanation:

Solved,

Diameter of the well = 7m

So, radius of the well = 7 ÷ 2 = 3.5m

Height of the well = depth of the well = 20m

We know that the well is in the shape of a7 cylinder.

So,

Quantity of the Earth taken out = Volume of the well = πr²h

→ 22/7 × 3.5² × 20

→ 22/7 × 12.25 × 20

→ 22/7 × 245 = 770m³

Hence,

Amount of Earth taken out is 770 m³

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If the answer is correct do as you wish and if not correct please inform me.

Answer 2

Answer:

Step-by-step explanation:

Since, Volume of well = Volume of earth dug out and Radius of well=4/2=2m

Volume of cylindrical well or earth dug out =

Pi×2^2×10

Pi×40

22/7×40=125.66 m^2

Cost of plastering =CSA of well ×5m^2

=(2×Pi×2×10)×5

=125.71×5

=Rs.628.55