The sale price of the shirt is 15% off the original price of $19.99, which is:
$19.99 x 0.15 = $2.999 (rounded to $3)
So each shirt costs:
$19.99 - $3 = $16.99
To find the cost of 3 shirts, we can multiply the cost of one shirt by 3:
$16.99 x 3 = $50.97
Next, we need to add the sales tax. To do this, we first need to find 8% of the total cost (including the discount):
$50.97 x 0.08 = $4.08
Finally, we add the sales tax to the total cost:
$50.97 + $4.08 = $55.05
Therefore, Jason would pay $55.05 for 3 of the shirts with an 8% sales tax.