Question

The internal measures of a cuboidal room are 12m × 9m × 6m. find the total cost of whitewashing all four walls of a room, if the cost of whitewashing is rs. 5 per m². what will be the cost of white washing if the ceiling of room is also white washed?​

Answer 1

Step-by-step explanation:

The internal measures of a cuboidal room are 12m × 9m × 6m. find the total cost of whitewashing all four walls of a room, if the cost of whitewashing is rs. 5 per m². what will be the cost of white washing if the ceiling of room is also white washed?

Answer 2

$\large \sf \color{red}{SOLUTION :}$

Let the length of the room = $l$ = 12 m

Width of the room = $b$ = 8 m

Height of the room = $h$ = 4 m

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Area of the four walls of the room = Perimeter of the base × Height of the room

= $\sf{2(l + b) \times h}$

= $\sf{2(12 + 8) \times 4}$

= 2 × 20 × 4 = 160 m².

Cost of white washing per m² = Rs. 5

Hence, the total cost of white washing four walls of the room = Rs. (160 × 5) = Rs. 800

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Area of ceiling is 12 × 8 = 96 m²

Cost of white washing the ceiling = Rs. (96 × 5) = Rs. 480

So, the total cost of white washing = Rs. (800 + 480) = $\boxed{\sf{ Rs. ~1280}}$

Hope this helps uh! :)