For the first question, my difficult situation i'd faced with is when I's a group leader who had to make a final decision, it happened when we had to selected a new member but the person is whom others didn't like. So, why I should select this one.. Because of her real ability which she had proved to me. Then the important and seem hard was changing other members' feeling, open their hearts to allow her proving herself that she was not bad as others said. Finally, she could done it, both, to help our team project done well and perfectly and also proved herself. So, now she is one of our best friend.
Next question:
I prefer to work in team because working with others help work goes well and done easier faster. We can use our ability to done together to achieve the goal.