At a certain theater, the cost of each adult's ticket is $5 and the cost of each child's ticket is $2. What was the average (arithmetic mean) cost of all the adults' and children's tickets sold at the theater yesterday?
(1) Yesterday the ratio of the number of children's tickets sold at the theater to the number of adults' tickets sold at the theater was 3 to 2.
(2) Yesterday 80 adults' tickets were sold at the theater.