I tried the jQuery Cert Example Questions today and I did not like those questions...
Well first, the question about JQuery's css() and style() appears twice in 2 different versions, so checking the users know-how is in this case a dupe and not knowing this single command would cause 2 false answers but that would not reflect the coverage you should be aiming at.
And second the question for `$(":disabled")` has as correct answer `All disabled input elements`, but that is not correct, first input-elements are specific elements tagged with `input` in the given query though nothing is declaring input, so this query would also find select-tagged list that are disabled. So this is very misleading and simply put a false answer since even your own definition from the w3schoolds-website says:
The :disabled selector matches every disabled element (mostly used on form elements).
I'd be happy if you would improve the questions, after all you want to make money with them