cindy and her younger sister have total of less than $15. cindy has twice as much money as her younger sister. let x represent the amount of money cindys younger sister has. tell whether each statement is true or false

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