Question

How many m³ of soil has to be excavated from a rectangular well 28cm deep and whose base dimensions are 10cm and 8m. Also, find the cost of plastering its vertical walls at the rate of Rs. 15/m².

Answer 1

= 10m 

b = 8 

h = 28m 

Volume of soil = volume of cuboid 

= l × b × h = 10 × 8 × 28 = 2240 m³ 

2240 m³ of soil has to be excavated. 

Area to be plastered = L.S.A of cuboid 

= 2h(l + b) 

= 2 ×28(10 + 8) 

= 56 × 18 = 1008m² 

The cost of plastering 1m² = Rs. 15 

∴The cost of plastering = 15 × 1008 = Rs. 15,120