Question

The length, breadth and height of a room are 5 m, 4m and 3 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs 7.50 per m²(square)

Answer 1

Answer:

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Answer 2

S O L U T I O N :

$\underline{\bf{Given\::}}$

• Length of the room, (L) = 5 m
• Breadth of the room, (B) = 4 m
• Height of the room, (H) = 3 m
• Rate of ceiling = 7.50 /m²

$\underline{\bf{Explanation\::}}$

As we know that formula of the total surface area of ceiling of white washing;

$\boxed{\bf{S.A.\:of\:4\:walls = 2(l+b) h + lb}}$

A/q

$\mapsto\tt{Surface\:area\:of\:painted\:walls = 2(l+b)h + lb}$

$\mapsto\tt{Surface\:area\:of\:painted\:walls = 2(5 + 4) 3 + 5 \times 4}$

$\mapsto\tt{Surface\:area\:of\:painted\:walls = 2(9) 3 + 5 \times 4}$

$\mapsto\tt{Surface\:area\:of\:painted\:walls = 54+20}$

$\mapsto\bf{Surface\:area\:of\:painted\:walls = 74\:m^{2}}$

Now,

⇒ Total cost = Rate × Area

⇒ Total cost = 7.50 × 74

⇒ Total cost = Rs.555

Thus,

The total cost of white washing for walls of the room will be Rs.555 .