Answer: The answer is (C) 7%.
Step-by-step explanation: Given that Santino bought a book for $23.54 and the original price of the book was $22. We are to find the sales-tax rate of the book.
The sales tax on the book will be
\(S=\$23.54-\$22=\$1.54.\)
Therefore, the sales tax rate will be
\(r=\dfrac{1.54}{22}\times 100\%=\dfrac{154}{22}\%=7\%.\)
Thus, the correct option is (C).
