The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs.7.50 per sq.m.
Answers
Length, breadth and height of a room are 5 m, 4 m and 3 m.
Area of four walls of the room =2h(l+b)
=2×3(5+4)
=6(9)
=54 sq m
Area of the ceiling =l×b
=5×4
=20 sq cm.
Total area of the four walls and the ceiling of the room
=54+20
=74 sq cm
Cost of white washing = Rs 7.50 per sq m
Total cost of white washing =74×7.50= Rs 555
hope it helps you.
QuestioN :
The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs.7.50 per sq.m.
GiveN :
- Length of the room (l) = 5 m
- Breadth of the room (b) = 4 m
- Height of the room (h) = 3 m
To FiNd :
- The cost of white washing the walls of the room and the ceiling at the rate of Rs.7.50 per sq.m.
ANswer :
The cost of white washing the walls of the room and the ceiling at the rate of Rs.7.50 per sq.m is Rs. 555
SolutioN :
Area of walls of the room = Lateral surface area of cuboid
= 2h(l + b)
= 2 × 3(5 + 4)
= 6 × 9
= 54 sq.m
Area of ceiling = Area of base of the cuboid
= lb
= 5 × 4
= 20 sq.m
Area to be white washed = (54 + 20) sq.m = 74 sq.m
Given that, the cost of white washing 1 sq.m = Rs. 7.50
∴Hence, the total cost of white washing the walls and ceiling of the room = 74 × Rs. 7.50 = Rs. 555
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