Let, number of children are x and number of adult are y.
Total number of seats, T = 180.
x + y = 180 ....1)
Tickets to a 3D movie cost $12.50 for adults and $8.50 for children.
So, total amount :
8.5x + 12.5y = A
8.5x + 12.5y = 1826 ....2)
Solving equation 1) and 2) , we get :
8.5x + 12.5( 180 - x ) = 1826
8.5x - 12.5x + 2250 = 1826
-4x = -424
x = 106
y = 180 - 106 = 74
Therefore, the number of adult tickets and the number of children's tickets that were sold are 74 and 106.
Hence, this is the required solution.