Question

Question 5.
The length, breadth and height of a room are 10 m, 8 m and 6 m respectively. Find the cost of white
washing the walls of the room and the ceiling at the rate of Rs.7.50 m2.​

Answer 1

Answer:

There are four walls  and one ceiling

So for ceiling we have to mutiply length with breadth

Area of ceiling= 10x8= 80 sq m

cost of white  washing the ceiling = 80x7.50= Rs 600/-

We find the perimeter of the room and when we mutiply with height we can find the area of four walls.

So perimeter= 2(10+8)= 32 metres

Area of walls of the room= 32x 6= 192 sq m

cost of white  washing the walls of the room= 192x 7.50= Rs 1440/-

Step-by-step explanation:

Hope it helps

Answer 2

Answer:

$\huge \bold { \underline{Given}}$

• Length of room-10m
• Breadth of room-8m
• Height of room-6m

$\huge \bold{ \underline{To Find:-}}$

The white washing of room and Ceiling at the rate of Rs.7.50m².

$\huge \bold{ \underline{ \underline{Solution:-}}}$

Area to be white- washed

= Area of cuboid-Area of base

$\normalsize{ = 2(lb + bh + lh) - l \times b}$

$= 2(lb) + 2(bh) + 2(lh) - lb$

$= lb + 2(bh) + 2(lh)$

$= {(5 \times 4) + (2 \times 4 \times 3) + (2 \times 5 \times 3)} {m}^{2}$

$= (20 + 24 + 30) {m}^{2}$

$= 74 {m}^{2}$

Cost of white-washing per m² area=Rs.7.50

Cost of white washing 74m² area =Rs(74×7.50)

=Rs555