Delta charges some of the highest change and cancellation fees among domestic airlines. Delta Air Lines also charges a $200 change fee for paid domestic flights (including to the U.S. Virgin Islands and Puerto Rico), and up to $450 for international flights.
Trouble is anything that causes difficulty, worry, and inconvenience, or that prevents you from doing something. If you have trouble getting along with a classmate, it is hard to be friendly with him or her. Whether you have trouble finding your shoes, you're in trouble with your teacher, or you go to a lot of trouble buying the kind of tea your sister likes, you face an annoying â and possibly distressing â difficulty.
Wicked Problems. A wicked problem is a social or cultural problem that is difficult or impossible to solve for as many as four reasons: incomplete or contradictory knowledge, the number of people and opinions involved, the large economic burden, and the interconnected nature of these problems with other problems.