Eva treated her co-workers to a meal that cost $54.35. eva knew that when the bill came, she would need to pay hampton sales tax of 5% and would want to leave a 20% tip on the original $54.35. including tax and tip, how much did eva's meal cost?

I got $54.60. But I am not 100% sure but we just did these kind of problems In my school and my grade in math is a 92%.

The tax for the meal would be:
54.35 / 100 = 0.5435 <--- that is the total amount she'd have to pay per percent. Since the tax is 5%, we have to multiply that (0.5435) by 5. 
0.5435 x 5 = 2.7175 <--- this is what she has to pay for Hampton taxes for her meal. 

If she wants to leave 20% of the original bill, we can use the first number we found. Since 0.5435 = 1% of the bill, all we need to do to find the tip would be multiply 0.5435 by 20. 
0.5435 x 20 = $10.87 <--- this is the tip total. 

If we add all those totals together, her total bill would come out to be:
2.7175 (taxes) + 10.87 (tip) + 54.35 (food cost) = 67.9375. 
If you were required to round, it would be $68.00, or $67.94, depending on how you were supposed to round.