Question

The length, breadth,and height of a room are 5m,4m,and 3m resp. Find the cost of white washing the walls of the room and the ceiling at the rate of 7.50 paise per meter square

Answer 1

Area of walls + Area of ceiling of room
= 2lh + 2bh + lb
= [2 × 5 × 3 + 2 × 4 × 3 + 5 × 4] m2
= (30 + 24 + 20) m2
= 74 m2
Now Cost of white-washing per m2 area = Rs 7.50
So Cost of white-washing 74 m2 area = Rs (74 × 7.50)
= Rs 555

Answer 2

Hello..

Length, breadth and are 5 m, 4 m and 3 m.

Area of four walls of the room

= 2h(l + b)
= 2 x 3 (5 + 4) 
= 6(9)
= 54 sq m

ceiling

= l x b
= 5 x 4
= 20 sq cm.

Total area of four walls and the ceiling

= 54 + 20
= 74 sq cm

Cost of white washing = Rs 7.50 per sq m

Total cost of white washing = 74 x 7.50

= Rs 555