I really need to add more details to a question and the next time I will be able to use a computer will be in two days. Anyway I can do it on my iPhone 5 via an app or something? Thanks for answering.
Firstly switch Desktop(At the bottom of yahoo answers screen) if you're on mobile site/screen. Click My activity or your pic of avatar and now you will your profile on there click My Questions and you will see pencil icon Edit (bottom of question) under of questions after open or clicking question then use edil tab to adding additional details or checked this explanation photo link. http://yanswersblog.com/Pictures/extendq.jpg