16. (15 points) Uncle Li contracted 12 mu of paddy fields, with a yield of 660 kilograms per mu. Aunt Lin contracted 2 mu less of paddy fields than Uncle Li, and the total yield of rice is 420 kilograms less than Uncle Li's. Questions:
(1) What is Uncle Li's total yield of rice in kilograms?
(2) How much less is Uncle Li's yield per mu compared to Aunt Lin's?