# The Inner Diameter of a Circular Well is 3.5 M. It is 10 M Deep Find: (I) Inner Curved Surface Area. (Ii) the Cost of Plastering this Curved Surface at the Rate of Rs. 40 per M^2 - Mathematics

The inner diameter of a circular well is 3.5 m. It is 10 m deep Find:
(i) inner curved surface area.
(ii) the cost of plastering this curved surface at the rate of Rs. 40 per m^2

#### Solution

Inner radius (r) of circular well=1.75m

Depth (n) of circular well =10m

(1) Inner curved surface area = 2pirh

=2xx22/7xx1.75xx10m^2

=(144xx0.25xx10)m^2

=110m^2

(2) Cost of plastering 1m^2 area = Rs.40.

Cost of plastering 110m^2 area= Rs (100xx40)

=Rs.4400

Concept: Surface Area of Cylinder
Is there an error in this question or solution?

#### APPEARS IN

RD Sharma Mathematics for Class 9
Chapter 19 Surface Areas and Volume of a Circular Cylinder
Exercise 19.1 | Q 8 | Page 8

Share