a. The first expression to calculate Conor's total cost would be: t + 0.15t (the cost of the ticket plus the 15% amusement tax)
The second expression to calculate Conor's total cost would be: t * 1.15 (the cost of the ticket multiplied by 1.15, which includes the 15% tax)
b. Let's choose t = $12.50. Using the first expression, Conor's total cost would be: 12.50 + 0.15(12.50) = 12.50 + 1.875 = $14.375. Rounded to the nearest penny, Conor's total cost would be $14.38.
c. Let's assume t = $17.50. Using the second expression, Conor's total cost would be: 17.50 * 1.15 = $20.125. Rounded to the nearest penny, Conor's total cost would be $20.13. Therefore, a possible value of t to make Conor's total cost fall between $17.50 and $20.00 would be t = $17.50.