Thank you for your answer Fiona!
We just recently did Kent mock test and my daughter got right 139 out of 180 questions, which is 74%. They told us it is pass but other information is that you need a minimum 82% to pass or 90% to guarantee. And in a real Kent test 420 questions in 4 hours and for Bexley it's 280 questions in 2 hours!
So I'm confused:(
The person advising you might be referring to a Bexley top 180 score. If you score in the top 180 you are 'guaranteed' a place at a Bexley grammar provided you put it down on your CAF. If you are within distance you just need a pass. Distances for this year have been discussed on this Forum, eg Sid n Chid came out 4.01 miles but that might change by September.
Kent test is extended by the essay that is only used for borderline cases. For the OOC sitters the arrival time was about 8.30, departure for us 1.30+ but some of that was delays and break times. Again, Kent just requires a pass unless you are looking at the schools that offer places based on score and some places to OOC candidates in which case a high score is needed for OOC.