Answer:
rate =16.5 %
Explanation:
First determine how much you gave as a tip
40-34.35 = 5.65
The order * tip rate = tip
34.35 * rate = 5.65
Divide each side by 34.35
34.35 * rate / 34.35 = 5.65/34.35
rate =.164483261
Change to percent form
rate = 16.4483261%
To the nearest tenth
rate =16.5 %