The cost of a single ticket depends on the number of tickets, t, purchased in a group, as represented by the function c(t). c(t) = startlayout enlarged left-brace 1st row 1st column dollar-sign 18.50 2nd column 1 less-than-or-equal-to t less-than 12 2nd row 1st column dollar-sign 16.00 2nd column 12 less-than-or-equal-to t less-than 20 3rd row 1st column dollar-sign 14.50 2nd column 20 less-than-or-equal-to t endlayout what is the total cost for 20 tickets? $14.50 $16.00 $290.00 $320.00