it all depends, with my previous boyfriend it would take me less than 10 minutes, but it wasn't a very satisfactory orgasm, but with my current boyfriend it takes me longer, sometimes over 30 minutes, but they are WAY stronger
My average orgasm definitely takes longer than 30 minutes but I tend to take my time and make the moment last as long as possible because I enjoy my sex life so much.
It sooo depends on circumstance and how turned on I am. I reach orgasm better when I am on top too. If I am on top it definitely takes less than 10 minutes. Any other way and it may take a lot longer. With a crappy toy and not my honey it can take well over 30 mins. Even with a good toy I will take longer than during the real thing.