Johnny bought an oil painting originally priced at $80 but on sale for for 50% off. After 10% sales tax, what was the total cost?

$44

Step-by-step explanation:

Original price = $80

Discount on sale = 50%

Discounted price = (1 - 50%) * original price

Discounted price = 0.5 * $80 = $40

Sales tax = 10%

Sales tax amount = 0.1 * $40 = $4

Total cost = discounted price + sales tax amount

Total cost = $40 + $4 = $44