How many cubic metres earth will be excavated from a cuboidcal well of dimensions 20m × 20m × 15m? Also, find the cost of plastering its vertical surface at the rate of rupees 1.50 per sq m.
Answers
The amount of excavated earth is 6000 m³.
The total cost of plastering is ₹1800.
Given data :
The length of the well is 20 metres.
The width of the well is 20 metres.
The height of the well is 15 metres.
The cost of plastering is ₹1.5 per square metre.
• Firstly,we have to calculate the volume of the well by using the following mathematical formula :
Volume = length×width×height
= 20×20×15
= 400×15
= 6000 m³
So,a total of 6000 m³ earth was excavated from the well. (Answer)
• Now,we have to calculate the vertical wall surface area by using the following formula :
Vertical wall surface area = Base perimeter × Height
= (4×length)× Height [ the base has similar length and width,so it's a square,which has a perimeter of 4×side]
= (4×20)×15
= 80×15
= 1200 m²
• Now,we have to calculate the total cost of plastering by using the following mathematical formula :
Cost = total surface area × cost per metre²
= 1200×1.5
= ₹1800
So,the total cost of plastering the vertical walls of the well is ₹1800 (answer).