Answer: $5 per ticket
To calculate the unit rate of the tickets sold, then we need to find the slope of the graph
Slope = rise / run
To calculate the slope, we need to pick some points on the graph
From the graph, we picked two points which are ( 20, 100) and (40, 200)
rise = y2 - y1
run = x2 - x1
Where x1 = 20, y1 = 100, x2 = 40, and y2 = 200
Slope = 200 - 100 / 40 - 20
Slope = 100 / 20
Slope = 5
Hence, the uint rate of the tickets sold is $5
The answer is $5 per ticket