Question

The height of a room is 40% of its semi - perimeter. It costs 260 rupees to paper the walls of the room with paper 50 cm wide at 2 rupees per metre allowing an area of 15 m^2 for doors and windows. The height of the room is ?​ Plz don't copy.​

Answer 1

Answer:

4m

Step-by-step explanation:

room be l, b and h respectively.

Then, h = 0.4 (l + b)

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

= 2 (l + b) × 0.4 (l + b) = 0.8 (l+b)2

Required area where paper has to be pasted

= 45 (l+b)2 - 15

Now, area of paper = area of wall

Length × breadth = 45 (l+b)2 - 15

Length = 45(l+b)2−1512

Given, 2 [ 45(l+b)2−15] × 2 = 260

=> 165(l+b)2 - 60 = 260

=> 165(l+b)2 = 320

=> (l+b)2 = 100

=> (l+b) = 10

∴ h = 0.4 × 10 = 4 m