Silver Cups

A lady has two silver cups, and only one cover for both.  The first cup weighs 16 ounces, and when it is covered it weighs 3 times as much as the second cup; but when the second cup is covered, it weighs 4 times as much as the first.  What is the weight of the second cup and of the cover?

Standard Arithmetic, William Milne, 1892

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