The length, height and thickness of a wall are 8 m, 4 m and 35 cm resp

1.	The length, height and thickness of a wall are 8 m, 4 m and 35 cm respectively. It contains one gate of size 3 m × 1 m and two windows of size 1.20 m × 1 m. Find the cost of building the wall at the rate of Rs 1500 per m3.
Answer» Given : Length of wall (l) = 8 m Thickness of wall (b) = 35 cm = 0.35 m Height of wall (h) = 4 m Volume of wall = l × b × h = 8 × 4 × 0.35 = 11.2 m³ Dimension of the gate in the wall = 2 m × 1 m × 0.35 ms [∵ Thickness of wall = 0.35 m] ∴ Volume of the gate in the wall = 2m × 1 m × 0.35 m = 0.7 m³ Measures of 2 windows in the wall = 1.20 m × 1 m × 0.35 m Volume of 2 windows in the wall =2 × 1.2 × 1 × 0.35 = 0.84 m³ Volume of wall with out a gate and two windows = 11.2 – (0.7 + 0.84) = 9.66 m³ ∵ Cost of building 1 m³ wall = Rs 1500 ∴ Cost of building 9.66 m³ wall = 1500 × 9.66 = Rs 14490 ∴ Hence cost of building the wall = Rs 14490

The length, height and thickness of a wall are 8 m, 4 m and 35 cm respectively. It contains one gate of size 3 m × 1 m and two windows of size 1.20 m × 1 m. Find the cost of building the wall at the rate of Rs 1500 per m3.

Answer»

Given :

Length of wall (l) = 8 m

Thickness of wall (b) = 35 cm

= 0.35 m

Height of wall (h) = 4 m

Volume of wall = l × b × h

= 8 × 4 × 0.35

= 11.2 m³

Dimension of the gate in the wall

= 2 m × 1 m × 0.35 ms [∵ Thickness of wall = 0.35 m]

∴ Volume of the gate in the wall

= 2m × 1 m × 0.35 m = 0.7 m³

Measures of 2 windows in the wall

= 1.20 m × 1 m × 0.35 m

Volume of 2 windows in the wall

=2 × 1.2 × 1 × 0.35 = 0.84 m³

Volume of wall with out a gate and two windows

= 11.2 – (0.7 + 0.84)

= 9.66 m³

∵ Cost of building 1 m³ wall = Rs 1500

∴ Cost of building 9.66 m³ wall

= 1500 × 9.66 = Rs 14490

∴ Hence cost of building the wall = Rs 14490