Question

Find the area of the four walls of a room whose length is 6 m, breadth 5 m and height 4 m. Also, find the cost of white-washing the walls, if the rate of white washing is Rs 5 per square metre. (Doors, windows and other openings ignored)

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Answer 1

Answer:

Lateral surface area= 2×h(l+b)

2 × 4 (6+5)

8×11 = 88m²

COST OF WHITE WASHING= 88×5 = ₹440

Step-by-step explanation:

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Answer 2

$\large\underline{ \underline{ \sf \maltese{ \: Question:- }}}$

• Find the area of the four walls of a room whose length is 6 m, breadth 5 m and height 4 m. Also, find the cost of white-washing the walls, if the rate of white washing is Rs 5 per square metre. (Doors, windows and other openings ignored)

$\large\underline{ \underline{ \sf \maltese{ \: Given:- }}}$

• Length = 6m
• Breadth = 5m
• Height = 4m
• Cost of White-Washing of 1 square metre = Rs, 5

$\large\underline{ \underline{ \sf \maltese{ \: Solution:- }}}$

$\quad { \boxed{ \sf{\bf{ Area \: of \: the \: four \: walls \: = \: 2 \: \times \: Height \: \times (Length \: + \: Breadth) }}}}$

$\qquad \quad {:} \longrightarrow \sf{\sf{Area \: of \: the \: four \: walls \: = \: 2 \: \times \:4\: \times (6 \: + \: 5) {m}^{2} }}$

$\qquad \quad {:} \longrightarrow \sf{\sf{Area \: of \: the \: four \: walls \: = \: ( \: 4 \: \times \: 11 \: ) {m}^{2} }}$

$\qquad \quad {:} \longrightarrow \sf{\sf{Area \: of \: the \: four \: walls \: = \:\: 88 \: {m}^{2} }}$

$\qquad\quad {:} \longrightarrow \underline \red{\boxed{\sf{ Area \: of \: the \: 4\: walls \: = \: 88 {m}^{2}}}}$

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Cost of White Washing of 1 square metre = Rs,5

$\quad { \boxed{ \sf{\bf{ Cost \: of \: White \: Washing \: the \: Walls \: = \: 5 \: \times \: Area \: of \: Walls}}}}$

$\qquad \quad {:} \longrightarrow \sf{\sf{Cost \: of \: White \: Washing \: the \: Walls \: = \: 5 \: \times \: 88 }}$

$\qquad \quad {:} \longrightarrow \sf{\sf{Cost \: of \: White \: Washing \: the \: Walls \: = \: 440 }}$

$\qquad\quad {:} \longrightarrow \underline \red{\boxed{\sf{ Cost \: of \: White \: Washing \: the \: Walls \: = \: Rs, 440 }}}$

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$\begin{gathered}\begin{gathered}\qquad \therefore\: \sf{ Area \: of \: the \: 4\: walls \: = \underline {\underline{ 88 {m}^{2}}}}\\\end{gathered}\end{gathered}$

$\begin{gathered}\begin{gathered}\qquad \therefore\: \sf{ Cost \: of \: White \: Washing \: the \: Walls \: = \underline {\underline{ Rs, 440}}}\\\end{gathered}\end{gathered}$

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