This can be possible only if someone is over smart and reads other class books.
I mean who reads others standards books...atleast not 5 classes elder books!.If someone does they can be compared to Albert Einstein😂.One more way is that...if the teacher who is there gives her/him the answer paper and the child can copy everything but that's too bit that is also quite impossible because there are always 5 teachers there and I dont think 5 of them will help the student neither the student can write that much in few minutes..quite tough you know.