Question

A family eats out at a restaurant and the total for their meals is $73.89. They also pay sales tax of 5.8% and leave a tip for their server. If the family leaves a total of $93, which of the following might be a description of the service they received?
a.
They left a 10% tip, so the service was probably below average.
b.
They left a 15% tip, so the service was probably average.
c.
They left a 20% tip, so the service was probably above average.
d.
They left a 25% tip, so the service was probably outstanding.

Answer 1

First compute the sales tax: 5.8% of \$73.89 is 0.058×73.89 ≈ \$4.29.
So meal + tax ≈ 73.89 + 4.29 = \$78.18. They paid \$93, so the tip ≈ 93 − 78.18 = \$14.82.

Tip as a percent of the pre-tax bill: 14.82 / 73.89 ≈ 0.2006 ≈ 20%.

Thus choice c (they left a 20% tip, so the service was probably above average) is the best description.