Hi Commenwealth A.,
Let x = the number of tickets sold at $10
Let y = the number of tickets sold at $15
The number of tickets sold for $10 [(x)*$10] plus the number of tickets sold for $20 [(y)*$15] equals the total amount collected from ticket sales [$12,200]:
(x)*$10 + (y)*$15 = $12,200; [10x + 15y = 12,200]
The total number of tickets sold [x + y] is 1000
x + y = 1000
The matrix is:
|10 15 12200|
|1 1 1000 |
I bet you can solve it from here.
Ans.
|1 0 560|
|0 1 440|
I hope this helps, Joe.