Because whomever decided which questions are in the test are incompetent as fuck, as are the people who gave them that responsability.
The whole thing has a massive stink of being the indirect result of some posh cunt giving one of his post cunt mates a top position in the part of the Public Service he's responsible for.
In the UK at the level of the so-called "Public School" educated (in a perfect illustration of the level of deceit in that society, what they call "Public Schools" are in fact expensive Private schools) Cronyism is standard and Merit is at best secondary to Knowing The Right People.