Question

Length, breadth and height of a room are 15 m, 12 m and 8 m, respectively. Find the cost of white washing the room at the rate of 8 rupees per m*m, if it has a door measuring 4 m x1.5 m and two windows each measuring 3 m x 2.5 m.​

Answer 1

Answer:

Here is your answer:

Step-by-step explanation:

Given,

length =15 m,

breadth=12 m,

height =8 m.

So,volume of cuboid(room)=l×b×h

=(15×12×8)m

=1440 m

Again,

length =4 m

breadth =1.5 m.

So,area of rectangle( door )=l×b

=(4×1.5)m

=6.0 m

Now,

length =3 m

breadth =2.5 m.

So,area of window =l×b

=(3×2.5)m

=7.50 m.

.

. .area of the room=(1440+6+7.5)m^2

=1453.50 m^2

So,cost of white washing =1453.50×8

= Rs.11628 ...

........ Thank you........

Answer 2

Answer:White washing will happen to the walls, therefore we are going to exclude the surface area of the 2 windows and the door. The walls are rectangular, thus their surface area is length multiplied by the breadth.

Two walls measure 15m by 8m, while other two walls measure 12m by 8m.

Therefore, if we want to get the total surface area, we do:

2( 15m * 8m) + 2( 12m * 8m)

which is

(2 * 120 squared meters) added to (2 * 96 squared meters)

(240 squared metres + 192 squared metres) = 432 squared metres.

Remember to exempt the two windows and the one door, as the white washing will happen to the walls only. Therefore,

The surface area of the door will be, 4m × 1.5m, which gives you 6 squared metres.

The surface area of the 2 windows will be, 2( 3m × 2.5m) which is 15 squared meters.

We add the surface area of the windows and the door, which is, (15 + 6) squared metres = 21 squared metres.

Since our total surface area was 432 square meters, we want ti exempt the windows and the door, whose total surface area is 21 squared metres,hence we subtract, (432 - 21) which gives 411 squared metres.

411 squared meters is the total surface area of the walls only.

The white washing costs 8 rupees per squared metre, yet we have our surface area as 411 squared meters, hence, we multiply 411 m*m by 8 rupees ; 411 × 8 = 3288 rupees.

The total cost of the white washing will be 3288 rupees.

Step-by-step explanation: