A cylindrical vessel open at the top has diameter 20 cm and height 14 cm. Find the cost of tin-plating it on the inside at the rate of 50 paise per hundred square centimetre.
Given,
Diameter of base of cylinder = 20 cm
Radius of cylinder = 
Height of cylinder = 14 cm
Total surface area of cylinder = 
∴ Cost of tin painting it inside at rate 50 paise per cm2 = 
12