Final answer:
To calculate the new price of the book after a 20% decrease, multiply the original price by 0.8 (100% - 20%). The new price of the book, rounded to the nearest cent, is $19.96.
Step-by-step explanation:
To calculate the new price of the book after a 20% decrease, we need to multiply the original price by 0.8 (100% - 20%).
$24.95 x 0.8 = $19.96 (rounded to the nearest cent).
Therefore, the new price of the book, rounded to the nearest cent, is $19.96.