Question

Find the cost of constructing a tubewell 280m deep having diameter 3 M at rate of $4per{m}^3$. Also, find the cost of cementing its inner curved surface area at Rs 3 per m square.

Answer 1

Diameter of tube well = 3m
So its radius = $\frac{3}{2}=1.5m$
Depth of tube well = 280 m
So volume of tube well to be sink = $\pi r^{2}h=\frac{22}{7}\times 1.52\times 280=1980m^3$
Rate of sinking the tube well = Rs.3 per metre cube
So total cost of sinking the tube well = $1980\times 3=Rs.5940$
Inner curved surface area of tube well = $2\pi rh=2\times \frac{22}{7}\times 1.5\times 280=2640m^2$
Cost of cementing inner curved surface area of tube well = Rs. 2.50 per m square
So total cost of cementing the inner curved surface area = $2640\times 2.50=Rs.6600$.