Question

the measures of a cuboid room are 12m*8m*4m respectively. find the total cost of whitewashing all four walls of room.if the cost is rupees 5 per m sq

Answer 1

Internal Length (l), breadth (b) and height (h) of the cuboidal room are 12 m, 8 m and 4 m respectively.

The area of the surface on which white washing is done

= Area of the surfaces of four walls

= 2h (l + b) + 

= 2 × 4 m × (12 m + 8 m)

= 160 m2 

Cost of white washing per sq m = Rs 5.

Thus, the cost white washing the entire room = Rs (160 × 5) = Rs 800

Hope! This will help you.

Answer 2

It has been given that ,
Length of the room ( l )= 12 m
Its breadth( b ) =8m
And its height( h )=4m


As we know ,
Area of four walls = 2(l+b)h
=2(12+8)*4
=2*20*4
=160 m sq.

Now,
Cost of whitewashing 1 m sq.= Rs. 5
So , cost of whitewashing 160 m sq = Rs. 5*160
= Rs.800


So, Rs. 800 will be the cost of whitewashing all the four walls of that room .