Length = 20 m
Breadth = 15 m
Height = 10 m
To find:
Total costing to cover the walls
1) Only the walls of the rectangular hall are included when you covered it by the wallpaper, So;
The area of the hall to be covered = 2H(L+B)
= 2× 10(20+15)
= 2 ×10 × 35
= 700 m²
2) Rate of covering the wall is ₹ 60 / m²
Total expenditure = Area×rate
= 700 × 60
= ₹42000
Total costing to cover the walls ₹42000.