Answer choices are 90, 38, 83, and 76

Hi my sisters and brothers can tell me the answer because i don’t understand the question

15/16 as a decimal rounded to the nearest hundredth

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