Question

the length breadth and height of a room 5m 4m and 3m respectively.find the cost of white washing the walls of the room and ceiling at the rate of rs. 7.50per m2​

Answer 1

Answer :

• 74m² is the cost of white washing the walls of the room
• Rs.555 is Celling at the rate of Rs. 750 per m²

Given :

• Length of room = 5m
• Breadth of room = 4m
• Height of room = 3m

To find :

• The cost of white washing the walls of the room
• Celling at the rate of rs.750 per m²

Solution :

Given that, white washing the walls of the room and ceiling of the room so, white washing the wall of the room is the Area of cuboid and Celling of the room is the Area of base then,

Area of white washed = Area of cuboid - Area of base

As we know that,

• Area of cuboid = 2(lb + bh + lh)
• Area of base = l × b

where , l is length 5m , b is breadth 4m and h is height 3m

》Area of cuboid - Area of base

》2(lb + bh + hl) - lb

》2(lb) + 2(bh) + 2(lh) - lb

》lb + 2(bh) + 2(lh)

》[(5 × 4) + (2 × 4 × 3) + (2 × 5 × 3)]

》(20 + 24 + 30) m²

》74m²

Hence, 74m² is the cost of white washing the walls of the room

Now we have to find the ceiling of the room ,

Given ,

• Rate = 750 per m²

》Cost of white washing per m² = Rs.750

》Cost of white washing 74 m² area = 74 × 750 = Rs.555

Hence,

• 74m² is the cost of white washing the walls of the room
• Celling at the rate of Rs. 750 per m² is Rs.555