citi online tests

how easy are the online tests at citi?
i heard they were really hard..
i have done the practise tests on efinanacial careers and get about 14/24 everytime..
is that enough? or should i aim for higher?
the thing is, i've done these tests so many times and i have seen them before..im scared i'll score even worse for a test ive never seen before!!!
what advice would u guys give me?????