There can only be two outcomes that result from the coon being flipped because there’s only two sides.
your answer is d because the formula is Ax+By=C
We need 6.5% to a decimal so..
6.5% /100 = 0.065
$21.30 X 0.065 = 1.3845 tax on the shirt
So.. we add the price of the shirt, and the amount of tax on the shirt
$21.30 + 1.3845 = $22.6845
Answer = $22.68
The sum must be irrational in contradiction to it being rational