Final answer:
To find the actual cost of the calculator, first calculate the discounted price by subtracting 15% from the list price. Then, add 5% tax to the discounted price. The total cost, given the calculations, should be $89.25, but this does not match the response choices provided.
Step-by-step explanation:
The question asks us to calculate the actual cost of a scientific calculator after a 15% discount and a 5% sales tax. To determine the discount price, we subtract 15% from the list price of $100. Convert the percentage to a decimal (0.15) and multiply that by $100.
$100 × 0.15 = $15 (discount amount)
Subtract the discount from the list price to get the discounted price.
$100 - $15 = $85 (discounted price)
Next, calculate the sales tax on the discounted price. Convert 5% to a decimal (0.05) and multiply by $85.
$85 × 0.05 = $4.25 (sales tax amount)
Add the sales tax to the discounted price to get the total cost.
$85 + $4.25 = $89.25 (total cost)
However, this total cost is not one of the options provided, hence there might be an error in either the question or the response choices.