Karen paid $43.70 for a book. the price of the book was $40. what was the sales tax rate?

The sales tax rate is found dividing the sales tax by the sales price and multiplying by 100. Here you must find the sales tax first. Sales tax = value paid - price of the book = $43.70 - $ 40 = $ 3.70. Now divide $3.70 by $40 and multiply times 100 = (3.70 / 40) * 100 = 9.25%.