Mrs. Noah'a bill, before tax, is $50. The sales tax rate is 3%. Mrs. Noah decides to leave a 2% tip for the gate keeper based on the pre-tax amount. How much will the total bill be, including tax and tip?

Since the tip percentage is before tax, we can combine it with the sales tax percentage for a total of 5%. The answer can be found by either finding 105% of $50, or finding 5% of $50 and adding it back on. We'll do the second method. To get 5% of $50, multiply 50 by its decimal equivalent, 0.05. If done correctly, you should get $2.50. Add this back go the original $50 for a total of $52.50