You buy a gallon of milk that costs $3.50. The milk is discounted for 10% off. You also have to pay tax of 6.25% on the discounted price. What is the final cost?

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