$63.84
Explanation:
A book shop offers a discount on a book = 24%
The original price of the book = $84.00
we have to calculate 24% of $84 and then subtract the discount price in the original price.
Sam purchases this book = 84 -(24% × 84)
= 84 - ( 0.24 × 84)
= 84 - 20.16
= $63.84
Sam has to pay $63.84 if he purchases book.