Question

10. A room is 9 m long, 8 m broad and 6.5 m high. It has one door of dimensions 2mx1.5 and three windows each of
dimensions 1.5 m x 1m. Find the cost of white washing the walls at 3.50 per sq. metre. Please solve all questions... with the formulas and solution in the copy...​

Answer 1

..Question..

A room is 9 m long, 8 m broad and 6.5 m high. It has one door of dimensions 2 x 1.5 and three windows each of dimensions 1.5 m x 1m . Find the cost of white washing the walls at 3.50 per sq. metre.

..Answer..

☯︎ Given ,

ㅤㅤㅤLength of the room = 9m

ㅤㅤㅤBreadthㅤ"ㅤ " ㅤ " = 8m

ㅤㅤㅤHeight. ㅤ"ㅤ" ㅤ"ㅤ = 6.5m

☯︎ also ,

ㅤㅤㅤdimension of the door = 2 × 1.5

ㅤㅤㅤ•°• area of the door ㅤ = l × b

ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ= 2 × 1.5

ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ= 3 m²

☯︎ again ,

ㅤㅤㅤ dimension of the widow = 1.5 × 1

ㅤㅤㅤ •°• area of the window.ㅤ= l × b

ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ = 1.5 × 1

ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ = 1.5 m²

Total no. of windows = 3

•°• total area of window = ( 3 × 1.5 ) m²

ㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤㅤ = 4.5 m²

☯︎ Combining area of windows and door

we get

=> ( 4.5 + 3 ) m²

=> 7.5 m²

☯︎ Now ,

• Area of the room =>

= 2 ( lb + bh + hl )

= 2 { ( 9 × 8 ) + ( 8 × 6.5 ) + ( 6.5 × 9 ) }

= 2 ( 72 + 52 + 58.5 )

= 144 + 104 + 117

= 356 m²

☯︎ Excluding the area of door and windows

we get

=> ( 365 - 7.5 ) m²

=> 357.5 m²

cost of whitewashing per m² = Rs 3.50

•°• cost for whitewashing 357.5 m² is

= Rs ( 357.5 × 3.50 )

= Rs 1251.25

_____________________

Give a look here :-

• Surface area of cuboid = 2 ( lb + bh + hl )
• Volume of cuboid = l × b × h

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ㅤㅤㅤㅤ ꧁ ʙʀᴀɪɴʟʏ×ᴋɪᴋɪ ꧂