The cost of preparing the walls of a room 12m long at the rate of Rs 1

1.	The cost of preparing the walls of a room 12m long at the rate of Rs 1.35 per square metre is Rs 340.20 and the cost of matting the floor at 85 paise per square metre is Rs 91.80. Find the height of the room.
Answer» Given details are, Length of room = 12 m Let width of room be ‘b’ m Let height of room be ‘h’ metre Now, Area of floor = 12×b m² = 12b m² Cost of matting the floor at the rate of 85 paise per square metre = Rs 91.80 12b × 0.85 = 91.80 12b = 91.80/0.85 12b = 108 b = 108/12 = 9m Now, Breadth of room = 9m Area of 4 walls = 2 (l×h + b×h) = 2 (12×h + 9×h) = 2 (12h + 9h) = 2 (21h) = 42h m² Cost for preparing walls at the rate of Rs 1.35 per square metre = Rs 340.20 42h × 1.35 = 340.20 42h = 340.20/1.35 42h = 252 h = 252/42 = 6m ∴ Height of room is 6m.

The cost of preparing the walls of a room 12m long at the rate of Rs 1.35 per square metre is Rs 340.20 and the cost of matting the floor at 85 paise per square metre is Rs 91.80. Find the height of the room.

Answer»

Given details are,

Length of room = 12 m

Let width of room be ‘b’ m

Let height of room be ‘h’ metre

Now,

Area of floor = 12×b m² = 12b m²

Cost of matting the floor at the rate of 85 paise per square metre = Rs 91.80

12b × 0.85 = 91.80

12b = 91.80/0.85

12b = 108

b = 108/12

= 9m

Now, Breadth of room = 9m

Area of 4 walls = 2 (l×h + b×h)

= 2 (12×h + 9×h)

= 2 (12h + 9h)

= 2 (21h)

= 42h m²

Cost for preparing walls at the rate of Rs 1.35 per square metre = Rs 340.20

42h × 1.35 = 340.20

42h = 340.20/1.35

42h = 252

h = 252/42

= 6m

∴ Height of room is 6m.