Question

Find the cost of painting four walls and ceiling of a room of dimensions 5m, 4m and 3m at rate of Rs 20/ sq m. *
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Answer 1

${\boxed{\underline{\underline{\underline{Question:-}}}}}$

⇒ Find the cost of painting four walls and ceiling of a room of dimensions 5m, 4m and 3m at rate of Rs. 20/ sq m.

${\boxed{\underline{\underline{\underline{Given:-}}}}}$

⇒ Dimensions of the room :

   5m

   4m

   3m

⇒ Cost of painting per m² = Rs. 20

${\boxed{\underline{\underline{\underline{To\:Find :-}}}}}$

⇒  The cost of painting four walls and ceiling of this room

${\boxed{\underline{\underline{\underline{Solution:-}}}}}$

⇒ $\sf Total\;Surface\;Area\;to\;be\;Washed\;=\;$

$\sf LTA \; + \; Area\;of\;the\;base$

$= \sf 2 (l+b)h \; + lb \\\\= 2 ( 5 + 4 ) \times 3 + 5 \times 4 \\\\= 74 m^{2}$

⇒ $\sf Cost\:of\:Whitewashing$

$\sf = Rs. (74\times 20) \\\\= Rs. 1480$

Answer 2

Answer:

Given :-

$\sf \: Length \: of \: room = 5 m$

$\sf \: Breadth \: of \: room = 4 m$

$\sf \: Height \: of \: room = 3 m$

To find:-

Find the cost of painting the four walls and ceiling of a room

Solution:-

Length of room = 5 m

Breadth of room = 4 m

Height of room = 3 m

Area of 4 walls+area of ceiling = 2(l+b)h+lb

Area of 4 walls+area of ceiling = 2(5+4)(3)+(5 × 4)2(5+4)(3)+(5×4)

Area of 4 walls+area of ceiling = 74 sq.m.

Cost of painting 1 sq.m. = Rs.10

Cost of painting 74 sq.m. = 74 \times 10 = Rs.74074×10=Rs.740

Hence The cost of painting the four walls and ceiling of a room is Rs.740