Question

the diameter of a well is 2.1 M and is 14m Depth find the cost of plastering it at ₹5 per square metre

Answer 1

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Answer 2

Given :

The diameter of a well is 2.1 M and is 14m Depth

To Find :

find the cost of plastering it at ₹5 per square metre

Solution:

Diameter of well = 2.1 m

Radius of well = $\frac{2.1}{2} = 1.05 m$

Depth of well = 14 m

Curved surface area of well = $2 \pi r h= 2 \times \frac{22}{7} \times 1.05 \times 14=92.4 m^2$

Cost of plastering 1 sq.m. = Rs.5

Cost of plastering 92.4 sq.m. = $5 \times 92.4 =462$

Hence the cost of plastering it at ₹5 per square metre is Rs.462