Find the cost of sinking a tube well 280 m deep, having diameter 3 m at the rate of Rs 3.60 per cubic metre.
Find the cost of sinking a tube well 280 m deep, having diameter 3 m at the rate of Rs 3.60 per cubic metre. Find also the cost of cementing its inner curved surface at Rs 2.50 per square metre.
Given data is as follows:
Height of the tube well = 280 m
Diameter = 3 m
Rate of sinking of the tube well $=$ Rs. $3.60 / \mathrm{m}^{3}$
Rate of cementing $=$ Rs. $2.50 / \mathrm{m}^{2}$
Given is the diameter of the tub well which is 3 metres. Therefore,
r = 3/2 m
Volume of the tube well $=\pi r^{2} \mathrm{~h}$
= 22/7 × 3/2 × 3/2 × 280
$=1980 \mathrm{~m}^{2}$
Cost of sinking the tube well = Volume of the tube well × Rate of sinking the tube well = 1980 × 3.60
= Rs. 7128
Curved surface area = 2πrh
= 2 × 22/7 × 3/2 × 280
$=2640 \mathrm{~m}^{2}$
Cost of cementing = Curved Surface area × Rate of cementing
= 2640 × 2.50
= Rs. 6600
Therefore, the total cost of sinking the tube well is Rs.7128 and the total cost of cementing its inner surface is Rs. 6600.