When I was doing my theory, I was revising it non stop for a month every single day until I had my test, but in short, I learnt to answer all the questions in 1 - 2 days. You should aim to get about 48/50 if you want to pass. Also during the test, they do throw new questions at you that aren't in the theory test app if you was unlucky like me.. but I still passed nevertheless. Aim for around 48/50 and you'll be fine.