In: Math
Tickets were sold at $4 for adults
Let the number of adults be 'a'
Tickets were sold at $2.50 for kids,
Let the number of kids be 'k'
480 tickets were sold for $1680
So,
Total tickets is 480

Sold at $1680

Multiplying 
 with
2.5


Subtracting 
with 




Substitute a=320 in 






Therefore,
Number of adult tickets sold = 320
Number of kids tickets sold = 160