A store manager instructs some new trainees that a water heater priced at $450 winds up costing a customer $495 once the sales tax is included. What is the sales tax percentage?
Sales tax = $495 - $450 = $45
Sales tax percentage = (Sales tax / original price of item) * 100
Sales tax percentage = ($45 / $450) * 100 = 10%
Therefore, the sales tax percentage is 10%.