Answer:
$48.30
Explanation:
the other answer's start is correct.
30% discount of $20 is 30/100*20 = $6
so, a shirt costs now only $14.
but sales tax is always calculated from the actual sales price. not from the original list price.
so, we need to calculate 15% of $14 (and not $20) as sales tax.
=> 15/100*14 = $2.10
a shirt now costs incl. sales tax $14 + $2.10 = $16.10
three shirts cost 3 * $16.10 = $48.30