Question

a hall of length 20m, breadth 10m and height 7m is to be painted along walls. how many cans of paint are required to paint the walls if from each can 30m² of area is painted? what will be the cost of painting if cost of each can is rs.75?​

Answer 1

2(l+b)h =2(30)×7=420m²

now required paint =420/30 = 14

so 14 cans are required

now cost = 75×14 = ₹1050

Answer 2

9450

see ...

area=2(l+b)h

=2(20+10)7

=2(30)7

=60×7=420

cans=4.20×30=126

Price=126×75=9450