The cost of preparing the walls of a room 12 m long at the rate of Rs 1.35 per square meter is Rs 340.20 and

Solution:

Given that,

Length of the room = 12m

Let the height of the room be 'h'

Area of 4 walls = 2(l + b)*h

According to the question

2(l + b) * h * 1.35 = 340.20

2(12 + b0 * h * 1.35 = 340.20

$(12+\mathrm{b}) * \mathrm{~h}=\frac{170.10}{1.35}=126 \ldots$

Also Area of the Floor = l * b

Therefore, l ∗ b ∗ 0.85 = 91.80

⇒ 12 ∗ b ∗ 0.85 = 91.80

⇒ b = 9 m ... (2)

Substituting b = 9m in equation (1)

(12 + 9) * h = 126; h = 6 m