For a certain play performance, adults' tickets were sold for $12 each and children's tickets were sold for $8 each. How many children's tickets were sold for the performance?
(1) The total revenue from the sale of adults' and children's tickets for the performance was $5,040.
(2) The number of adults' tickets sold for the performance was $$\frac{1}{3}$$ the total number of adults' and children's tickets sold for the performance.