13: A room is 40 m long, 25 m broad and 10 m high. Find the cost of wh

1.	13: A room is 40 m long, 25 m broad and 10 m high. Find the cost of white-washing allthe four walls, if the cost of white-washing is6 per m2
Answer» Length of that godown = 40mwidth of that godown = 25mthe height = 10m lateral surface area of a cuboid = 2h (l+b) = 2 (10){25 + 40}= 20 ( 65)= 1300m^2 area of the celling = length × breadth= 25 × 40= 1000m^2 total area to be whitewashed = total lateral area + area of the celling= 1300 + 1000=2300m^2 cost of whitewash per m^2 = Rs. 20total cost = total area to be whitewashed × cost of whitewashing per m^2= 2300 × 20= 26,000

13: A room is 40 m long, 25 m broad and 10 m high. Find the cost of white-washing allthe four walls, if the cost of white-washing is6 per m2

Answer»

Length of that godown = 40mwidth of that godown = 25mthe height = 10m

lateral surface area of a cuboid = 2h (l+b) = 2 (10){25 + 40}= 20 ( 65)= 1300m^2

area of the celling = length × breadth= 25 × 40= 1000m^2

total area to be whitewashed = total lateral area + area of the celling= 1300 + 1000=2300m^2

cost of whitewash per m^2 = Rs. 20total cost = total area to be whitewashed × cost of whitewashing per m^2= 2300 × 20= 26,000