Final answer:
The discount on the $40 dress is $10 (25% of $40), and the sale price after applying the discount is $30.
Step-by-step explanation:
To calculate the discount on a $40 dress that is marked down 25%, you perform the following steps:
- Convert the percentage to a decimal by dividing by 100, which gives us 0.25.
- Multiply the original price of the dress by the decimal to find the discount amount: $40 × 0.25 = $10.
- To find the sale price, subtract the discount from the original price: $40 - $10 = $30.
Therefore, the discount on the dress is $10 and the sale price of the dress is $30.