A solid steel ball of radius 1m is to be polished. The polishing workshop follows a tiered pricing scheme as follows:
• first 4m2 of surface area at ₹60 per square metre;
• next 4m2 at ₹50 per square metre;
• any remaining area at ₹40 per square metre.
(i) Compute the total surface area of the ball.
(ii) Using the given slab rates, calculate the complete polishing cost for the ball.