Ace the 2026 Armed Forces Arithmetic Challenge – Boost Your Reasoning and Conquer the AFCT!

To determine the sale price of a book originally costing $30 with a 20% discount, one must first calculate the amount of the discount. The discount can be found by multiplying the original price by the percentage that represents the discount.

1. Calculate the discount amount:

\[

\text{Discount} = \text{Original Price} \times \left( \frac{\text{Discount Percentage}}{100} \right) = 30 \times \left( \frac{20}{100} \right) = 30 \times 0.2 = 6

\]

2. Subtract the discount from the original price to find the sale price:

\[

\text{Sale Price} = \text{Original Price} - \text{Discount} = 30 - 6 = 24

\]

Thus, the sale price of the book after applying the 20% discount is $24. This price reflects the deduction made from the original cost, and therefore aligns with the provided calculation of the discount.