The outer diameter of a gas cylinder is 20 cm. Find the cost of the painting of its outer curved surface at ₹ 4 per square centimetre if the height of the cylinder is 70 cm.
The outer diameter of a gas cylinder is 20 cm. Find the cost of the painting of its outer curved surface at ₹ 4 per square centimetre if the height of the cylinder is 70 cm.