The cross-section of a tunnel, perpendicular to its length is a trapezium ABCD in which AB = 8 m, DC = 6 m and AL = BM. The height of the tunnel is 2.4 m and its length is 40 m. Find :

(i) the cost of paving the floor of the tunnel at ₹ 16 per m².

(ii) the cost of painting the internal surface of the tunnel, excluding the floor at the rate of ₹ 5 per m².

If the length of each side of a cube is reduced by 25%, then the ratio of the volumes of the original and the new cube is :

1. 64 : 1

2. 4 : 3

3. 64 : 27

4. 32 : 9

The length and the breadth of a cuboid are 60 cm and 50 cm respectively. If the total surface area of the cuboid is 14800 cm², then its height is :

1. 40 cm

2. 32 cm

3. 25 cm

4. 30 cm