1. The dimensions of a cinema hall are 100 m, 50 m and 18 m. How many persons can sit in the hall, if each person requires 150 cubic m of air?

1. A closed iron tank 12 m long, 9 m wide and 4 m deep is to be made. Determine the cost of iron sheet used at the rate of Rs 5 per metre, the sheet being 2 m wide.

1. The cost of papering the four walls of a room at 70 paise/sq. m is Rs 157.50. The height of the room is 5 m. Find the length and breadth of the room if they are in the ratio 4 : 1.

1. Each edge of a cube is increased by 50%. Find the percentage increase in the surface area of the cube.

A metal cube of edge 9 cm is melted and formed into three smaller cubes. If the edges of 2 smaller cubes are 1 cm and 6 cm, find the edge of the third smaller cube.

1. The diagonal of a cube is 12 cm. Find its surface area and volume.

1. A tank has a rectangular base of dimensions 300 m × 150 m. With what velocity per second must water flow into it through a pipe whose rectangular cross-section measures 8 dm × 5 dm so that the level may be raised 3\(\frac{1}{3}\)dm in 2 hours?

1. Three equal cubes are placed adjacently in a row. Find the ratio of the total surface area of the new cuboid to that of the sum of the surface areas of the 3 cubes.

1. A 4 cm cube is cut into 1 cm cubes. Calculate the total surface area of the small cubes. What is the ratio of the surface area of small cubes to that of the large cube?

1. One cubic metre piece of copper is melted and recast into a square cross-section bar, 36 metres long. An exact cube is cut off from this bar. Find the cost of this cube, if the cost of 1 cubic metre of copper is Rs 108.