For this case we must obtain the total amount of the bills:
![23.59 + 40.65 + 30.50 + 15.68 = 110.42](https://img.qammunity.org/2020/formulas/mathematics/middle-school/n1417po71leq3j2omfhwb9yxtwob6vy4dl.png)
Thus, the total of the bills was $ 110.42.
We make a rule of three to determine the percentage of tips received:
$ 110.42 -----------> 100%
$ 17.67 ------------> x
Where the variable "x" represents the percentage of tips received.
![x = \frac {17.67 * 100} {110.42}\\x = 16.0025](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pd30ilrnliwqcgpd8umm1vi68eimibpkwb.png)
So, he received 16% tip.
Answer:
Option D