It all depends on luck which means if your examiner is strict or relaxed, if your examiner takes you to motorway or not, if your examiner takes you to roundabouts or not, if the day of your test is downpouring or sunny, if on the day of your test you encounter crazy drivers, accidents, unusual situations and events. Luck plays an important role but most people are not aware of it but instructors know this. Do not worry if you fail first time, a person who passes at one test centre may fail at another. Take enough lessons and seek your instructor advice about the best test centre and time and date. Good luck is all you need!