Question

The cost of preparing 4 wall of a room 12m long at the rate of RS 1.35sq m is RS 340.20 and the cost of matting the floor at the
rate of 85p per sq mis RS 91.80 find the height.

Answer 1

Given,
1.35 × Area of 4 walls = 340.20
1.35 × 2h(l+b) = 340.20
1.35×2h(12+b)= 340.20
2.7h (12+b) = 340.20
32.4h + 2.7bh= 340.20 --(1)

85 paise = ₹ 0.85
0.85 × Area of floor = 91.8
0.85 × lb = 91.8
0.85 × 12 × b = 91.8
b = 91.8 /(0.85×12)
b = 9 m

From (1),
32.4h + 2.7×9h = 340.20
32.4h + 24.3h = 340.20
56.7h = 340.20
h = 6 m

Height = 6 metres.