Question

The cost of preparing the walls of a room 12 m long at the rate of 1.35 per square is 340.20 and the cost of matting the floor at 85 paise per square metre is 01.30. Find the height of the room.​

Answer 1

Answer:

Length of the room, l = 12 m

Let the breadth be b and height be h of the room.

Then,area of the room = l × b

= 12 × b = 12b m²

Cost of matting the floor = 85 paise/m²

= Rs 0.85/m² (in rupees)

Total cost of matting the floor = cost of matting the floor per m² × area of the room

= Rs 0.85 × 12b

0.85 × 12b = 91.80

12b = 91.80/0.85

12b = 108

b = 108/12

b = 9

Breadth of the room,b = 9 m

Area of walls of the room = 2h (l + b)

= 2h (12 m + 9 m)

= 2h (21)

= 42h m²

Cost of preparing the walls = Rs 1.35 / m²

Total cost of preparing the walls = Rs 1.35 × 42h

Rs 1.35 × 42h = Rs 340.20

42h = 340.20/1.35

42h = 34020/135

42h = 252

h = 252/42

h = 6