Answer: $69
Explanation:
Sales tax is charged after the discount.
The calculator was originally $75 and there is a 20% discount.
The discounted price is:
= 75 * (1 - 20%)
= 75 * 0.8
= $60
Now the sales tax applies. Total cost is:
= 60 * (1 + 15%)
= 60 * 1.15
= $69