Depends on the type of work and are which you are placed in as to the amount of flexibility that is available. Back office staff are able when suitable within their team/manager alter the 9-5 structure for various reasons.
Very flexible. People with kids can start early and leave early. Other people might work longer hours Monday-Thursday and take Friday off.
I tend to work a standard 38 hour week - sometime I will work more, but my leaders are flexible with me taking time off or leaving early if need be.
Very flexible. I can work from home if I need to.
I work more than my contract, but that is my choice. As a result, when I do require flexibility I am awarded that. It is very fair, I definitely give more than I take but I therefore don't feel guilty when I do ask for something
I control my own schedule and my line manager is flexible with times
Very flexible - I love my job so I work more than recommended