Question

Find the cost of papering the walls of a room 10 mtr. long, 5 mtr breadth and 5 mtr height with paper 75 cms
wide @ Rs. 10 per mtr

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Answer 1

Answer:

Rs.200

Step-by-step explanation:

If the walls of the room are papered

then the Lateral Surface Area of Cuboid=$LSA=2h(l+b)$

where $l=10m\\b=5m\\h=5m$

by substituting the values we get

$LSA=2h(l+b)\\=2*5(10+5)\\=10*15\\=150m^{2}$  

Given Length of paper sheet=75 cm= .75 m

Total amount of paper required=

$Lateral Surface Area /Length of Paper Sheet$

$150m^{2} /0.75m$

$=20m$

Cost of $1m$ of paper= Rs 10

Cost of $20m$ of paper= Rs $20*10$

= Rs $200$

Answer 2

Answer:

A room have 4 sides = 2 longer side and 2 shorter side

• 2 longer sides of area are = 2*(10*5)=100m^2
• 2 shorter sides of area are = 2*(5*5)=50m^2

total area= 100+50=150m^2

150m=15000cm

15000/75=200

@75cm^2=10

so, here 200*10=2000rs.

ans=2000rs