Mrs. katz could have saved money for her new computer rather than buying it on a credit card. what would have been the difference in the amount of time to pay for the computer and the amount of money ultimately spent?

Jada has a meal in a restaurant she adds up the prices listed on the menu for everything they ordered and gets a subtotal of $42.00. when the check comes, it says they also need to pay $3.99 in sales tax. what percentage of the subtotal is the sales tax