Question

The length, breadth and height of a room are 5 m, 4 m and 3 m, respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of ₹17.50 per m2.


Stammers Stay Away
​

Answer 1

$\huge\tt\red{A}\sf\pink{n}\tt\blue{S}\sf\green{w}\tt\purple{E}\sf\orange{r}\tt\orange{:}\huge\tt\red{}$

To find the cost of white washing the walls of room, we have to first find the Lateral Surface Area of the room.

We know that,

$\large {\textsf{ \textbf{Lateral Surface Area :- }}} \\ \: \sf{2(length + breadth) \times height}$

Thus, by applying the formula on your question, we can,

$\large {\textsf{ \textbf{Lateral Surface Area :- }}} \\ \: \sf{2( 5+ 4) \times 3} \\ \to \sf{2(9) \times 3} \\ \to \sf{18 \times 3} \\ \implies \bf \red{54}$

• Thus, the Lateral Surface Area of the room will be 54m².

★ Cost of White Washing :-

$\leadsto$ Here, we have been given that, the cost of white washing 1m² is Rs. 17.50.

• Now, we can use the unitary method;

$\mapsto$ 54m² × 17.50 = Rs. 945

• Hence, the cost of white washing the room will be Rs. 945.

From :-

#NAWABZAADA

To :-

#NAWABZAADI

Answer 2

Step-by-step explanation:

Answer

Length, breadth and height of a room are 5 m, 4 m and 3 m.

Area of four walls of the room =2h(l+b)

=2×3(5+4)

=6(9)

=54 sq m

Area of the ceiling =l×b

=5×4

=20 sq cm.

Total area of the four walls and the ceiling of the room

=54+20

=74 sq cm

Cost of white washing = Rs 7.50 per sq m

Total cost of white washing =74×7.50= Rs 555