Question

The diameter of a well is 2.8m. if it is 21m deep , find the cost of plastering it at Rs 6 per square meter. plz answer ​

Answer 1

Step-by-step explanation:

H=28m;

r=1.4m;

earth dug out=volume of cylinder=22/7*r*r*h;

= 22/7*1.4*1.4*28;

=172.48 m^3

hence 172.48m^3 of earth is dug out

The curved surface area of cylinder

=2*22/7*1.4*28;

=246.4

Cost of plastering=4.50*246.4

=Rs 1108.8