Find the cost of sinking a tubewell 280m deep, having diameter 3m 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.

Explanation

As we know that cost of sinking a tube well = Volume of the tube well x cost of sinking a tube well per cubic meter

`pir^2hxx3.60`

Here `r=1.5m` and `h=280m`

So cost of sinking a tube well = `22/7xx1.5xx1.5xx280xx3.60`

Rs.`7128`

Cost of cementing = Inner C.S.A of the tube well xx cost of cementing per square metre

`2xx22/7xx1.5xx280xx2.50`

Cost of cementing=Rs.`6600 `.