Question

The length breath and height of a room are 5m 4m and 3m respectively find the cost of washing the walls of the room and the ceiling at the rate of 12.50m square​

Answer 1

Step-by-step explanation:

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Answer 2

Given : The length breath and height of a room are 5m 4m and 3m respectively & The cost of white washing of room is at the rate of 12.50m² .

Exigency To Find : The cost of washing the walls of the room and the ceiling .

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As, We know that ,

$\underline {\bf{ Total \:Surface \:Area_{(Cuboid)}\:=\bigg( 2(lb + bh + lh )\bigg) }}$

$\underline {\bf{ \:Area\:of\;Base\:_{(Cuboid)}\:=\bigg( l \times b \bigg) }}$

⠀⠀⠀⠀Here , l is the Length of the Room , b is the Breadth of Room & h is the Height of the room .

Given that ,

• We have to white wash the walls and the ceiling of room .

Or ,

• $\star \:\:\boxed{\small {\sf{Area\:need\:to\:be\:white-washed \:= T.S.A_{Room} - Area\:of\:Base\:_{Room}}}}$

⠀⠀⠀⠀Or ,

• $\star \:\:\boxed{\small {\sf{Area\:need\:to\:be\:white-washed \:= 2(lb + bh + lh )- l\times b\:}}}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= 2(lb + bh + lh )- l\times b\:}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= 2(lb) + 2(bh) + 2(lh) - lb\:}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= lb + 2(bh) + 2(lh) \:}$

Here ,

• Length (l) of Room is 5m
• Breadth (b) of Room is 4 m
• Height (h) of Room is 3 m

⠀⠀⠀⠀⠀⠀$\underline {\frak{\star\:Now \: By \: Substituting \: the \: Given \: Values \::}}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= (5 \times 4) + 2(4\times 3) + 2(5\times 3) \:}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= (20) + 2(12) + 2(15) \:}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= 20 + 24 + 30 \:}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= 50 + 24 \:}$

$\::\longmapsto \sf{Area\:_{(White \:Washed)} \:= 74 m^2 \:}$

⠀⠀⠀⠀The cost of white washing of room is at the rate of per m² = Rs. 12.50.

⠀⠀⠀⠀The cost of white washing of room is at the rate of per 74m² = 74 × 12.50

⠀⠀⠀⠀The cost of white washing of room is at the rate of per 74m² = Rs. 925

Therefore,

⠀⠀⠀⠀⠀$\therefore {\underline{ \mathrm {  The\:Cost\:of\:White-Washing\:is\:\bf{Rs.\: 925}}}}$

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