To find out how much more the professional set of drawing pencils costs than the basic set, we can subtract the cost of the basic set from the cost of the professional set:
Cost of professional set: $27.49
Cost of basic set: $8.98
Difference:
$27.49 - $8.98 = $18.51
So, the professional set costs $18.51 more than the basic set. The correct response is $18.51.