Answer :
c = 3p
If 0 people buy tickets, the cost is $0. Plot the point (0,0)
If 3 people buy tickets, the cost is $9.
Plot the point (3,9)
Draw a straight line passing through (0,0) and (3,9).
If 0 people buy tickets, the cost is $0. Plot the point (0,0)
If 3 people buy tickets, the cost is $9.
Plot the point (3,9)
Draw a straight line passing through (0,0) and (3,9).