To answer this question, you need to write a linear equation (because the graph is a visibly straight line) that models this situation, then plug in 12.
The general format for a linear equation is y=mx+b, where m is the slope and b is the y intercept. The y intercept of a line is where it crosses the y axis; for this line, it crosses the y axis at (0, 0) so the y intercept is 0.
To find the slope, use the slope equation: (y2-y1)/(x2-x1). For y1, y2, x1, and x2, just pick any two points on the line. We will use (1, 30) and (2, 60):
(60-30)/(2-1)
30/1
30
The line is y=30x.
Plug in 12 for x:
y=30(12)
y=360
3). 360
Hope this helps!!