Question

Please solve this question correctly​

Answer 1

(i) Given

Depth of a well (h)=20m

and diameter =2m

Radius (r)=2/2=1m

Volume of earth dug out =πr

2

h=22/7×1×1×20=440/7m

3

(ii) Inner curved surface area =2πrh=2×22/7×1×20=880/7m

2

The cost of plastering at the rate of Rs.50 per m

2

=Rs.880/7×50=Rs.44000/7=Rs.6285.70

I hope it will be helpful.

Answer 2

Solution : (i) Given

Depth of a well (h)=20m

and diameter =2m

Radius (r)=2/2=1m

Volume of earth dug out =πr

2

h=22/7×1×1×20=440/7m

3

(ii) Inner curved surface area =2πrh=2×22/7×1×20=880/7m

2

The cost of plastering at the rate of Rs.50 per m

2

=Rs.880/7×50=Rs.44000/7=Rs.6285.70

I hope it will be helpful.