Please provide a step-by-step solution to the problem do not use any software in answering, just solve manually. Thank you.

A cement grinding mill A with a capacity of 50 tons per hour utilizes forged steel grinding balls costing P 12,000 per ton, which have a wear rate of 100 grams per ton cement milled. Another cement mill B of the same capacity uses high chrome steel grinding balls costing P30,000 per ton with wear rate of 10 grams per ton cement milled. Determine by calculation the more economical grinding mill, considering other factors to be the same.