A box at a miniature golf course contains contains 9 red golf balls, 6 green golf balls, and 7 yellow golf balls. What is the probability of taking out a golf ball and having it be a red or a yellow...

A box at a miniature golf course contains contains 9 red golf balls, 6 green golf balls, and 7 yellow golf balls. What is the probability of taking out a golf ball and having it be a red or a yellow golf ball?

Express your answer as a percentage and round it to two decimal places.