Yes there is indeed an IPAT test online. Personally I found this test pretty hard. In order to revise I suggest general word problems including mental maths and also knowing sequences I.e. Knowing what number comes next in a sequence, really easy e.g. 2, 4, 6, ?
You are not expected to get 100% in this test there is some room to make a few errors. Remember this test is timed as well so make sure you don't not run over.
Lastly you do not have to be some sort of maths genius to do this. Just revise what I have said and it should be ok