Find the cost of sinking a tube-well 280m deep, having a diameter 3m a

1.	Find the cost of sinking a tube-well 280m deep, having a diameter 3m at the rate of ₹ 15 per cubic metre. Find also the cost of cementing its inner curved surface at ₹ 10 per square metre.
Answer» It is given that Radius = 1.5m Height = 280m We know that Volume of the tube well = πr²h By substituting the values Volume of the tube well = (22/7) × (1.5)² × 280 So we get Volume of the tube well = 1980 m³ It is given that Cost of sinking the tube well = ₹ (15 × 1980) = ₹ 29700 We know that Curved surface area of tube well = 2 πrh By substituting the values Curved surface area of tube well = 2 × (22/7) × 1.5 × 280 So we get Curved surface area of tube well = 2640 m² It is given that So the cost of cementing = ₹ (10 × 2640) = ₹ 26400 Therefore, cost of sinking the tube well is ₹ 29700 and the cost of cementing is ₹ 26400.

Find the cost of sinking a tube-well 280m deep, having a diameter 3m at the rate of ₹ 15 per cubic metre. Find also the cost of cementing its inner curved surface at ₹ 10 per square metre.

Answer»

It is given that

Radius = 1.5m

Height = 280m

We know that

Volume of the tube well = πr²h

By substituting the values

Volume of the tube well = (22/7) × (1.5)² × 280

So we get

Volume of the tube well = 1980 m³

It is given that

Cost of sinking the tube well = ₹ (15 × 1980) = ₹ 29700

We know that

Curved surface area of tube well = 2 πrh

By substituting the values

Curved surface area of tube well = 2 × (22/7) × 1.5 × 280

So we get

Curved surface area of tube well = 2640 m²

It is given that

So the cost of cementing = ₹ (10 × 2640) = ₹ 26400

Therefore, cost of sinking the tube well is ₹ 29700 and the cost of cementing is ₹ 26400.