taxes or sum idk

Question

Mike works as a waiter in a restaurant. A couple comes in to have dinner and spends $45.00. Mike needs to add a 6% sales tax to the couple’s bill. Mike also knows they will tip 15% on the original bill. Adding the tax and the tip, what’s the total amount of money the couple will pay for their meal.

Answer 1

6% of $45 = $2.70 sales tax. $45 + $2.70 = $47.70

15% of $45 = $6.75

$47.70 + $6.75 $47.70 = $9.45 grand total spending, including government's take & waiter's tip.

or just add 6+15 = 21%

21% of $45 = $9.45