A cuboidal oil tin is 50 cm by 30 cm by 40 cm.Find the cost of the tin required for making 20 such tins.If the cost of tin sheet is Rs. 20 per square metre.

Find the cost of fencing a square park of side 250 m at the rate of Rs.20 per metre.

Shanti Sweets Stall was placing an order for making cardboard boxes for paking their sweets. Two sizes of boxes were required. The bigger of dimensions 25 cm by 20 cm by 5 cm and the smaller of dimensions 15 cm by 12 cm by 5 cm. 5% of the total surface area is required extra, for all the overlaps. If the cost of the cardboard is Rs 4 for 1000 cm^2 , find the cost of cardboard required for supplying 250 boxes of each kind.

A wooden box 1.5 m long, 1.25 m wide and 65 cm deep and open at the top is to be made. Find the cost of wood required for it, if Rs 30 is the cost of 1 metre square of wood.

A tent is the form of a cylinder of diameter 15 m and height 2.4 m, surmounted by a cone of equal base and height 4 m. Find the capacity of the tent and the cost of the canvas at Rs. 50 per square metre.

A joker’s cap is in the form of a right circular cone of base radius 7 cm and height 24 cm. Find the area of the sheet required to make 100 such caps if 1m^2 of sheet used for making cap costs Rs 700.

A cylindrical pillar is 50 cm in diameter and 3.5 m high. Find the cost of white washing its curved surface at the rate of Rs 40 per m^2 .