A flooring tile has the shape of a parallelogram whose base is 24 cm and the corresponding height is 10 cm. How many such tiles are required to cover a floor of area `1080 m^2`? (If required you can split the tiles in whatever way you want to fill up the corners).

A tank with a square base of area 1.0 m^-2 is divided by a vertical partition in the middle. The bottom of the partition has a smallhinged door of area 20 cm^2 . The tank is filled with water in one compartment, and an acid (of relative density 1.7) in the other, both to a height of 4.0 m. compute the force necessary to keep the door close.

The floor of a building consists of 3000 tiles which are rhombus shaped and each of its diagonals are 45cm and 30cm in length. Find the total cost of polishing the floor, if the cost per m^2 is Rs. 4.