Question

a door of length 5m and breadth 2m is fitted in a wall.The length is 6.5m and breadth 4.5m.Find the cost of whitewashing the wall,if the rate of whitewashing the wall is 50 per m.sq.
chapter:-area and perimeter

Answer 1

Length of door = 5m

Breadth =2m

Area of door = L×B = 5×2 = 10m²

Length of wall = 6.5m

Breadth of wall = 4.5m

Area of wall = L×B = 6.5×4.5 = 29.25m².

Area Is to be whitewashed= Area of wall- Area of door = 29.25-10 = 19.25m².

Cost of whitewashing for per meter = Rs50

Therefore,

Cost of whitewashing for 19.25 Meters = 50×19.25 = Rs 962.6

Answer 2

door dimension = 5 * 2 m² = 10 m²
now wall area = 6.5 * 4.5 = 29.25 m² 

now area to be whitewashed = 29.25 - 10 = 19.25 m² 
now cost of white washing = 50 * 19.25 = 962.5 /- rupee 


Hope this helps you 
thank you