Question

the length, breath and height of a room are 6m,4m and 3m respectively find the cost of white washing the four walls of the room has an extrance door measuring 2.5m multiple 1m which is not be white washing​

Answer 1

Step-by-step explanation:

Area to be whitewashed = area of four walls + area of ceiling

Formulas to be noted :−

Area of four walls =2 ( length + breadth ) × height

Area of ceiling = area of rectangle = length × breadth

In the question, length of the room =6m

breadth of the room =4.5m

height of the room =3m

On the basis of formulas given above :−

Area of four walls =2(6m+4.5m)x3m

Area of four walls =2(10.5m)x3m

Area of four walls =21mx3m

Area of four walls =63m

2

Area of ceiling =6m×4.5m

Area of ceiling =27m

2

Therefore, area to be whitewashed =63m

2

+27m

2

Area to be whitewashed =90m

2

Cost of whitewashing = rate at which area is being whitewashed × area to be whitewashed

Cost of whitewashing =Rs8/m

2

×90m

2

Cost of whitewashing =Rs8×90

Cost of whitewashing =Rs.720.