Getting full marks in the entrance examination definitely speaks about the level of knowledge those two students got. We can't say that it is luck. Without hard work and good attempt, you can't get 100% in any examination. If you are not sure of the answer you may do some guesswork. That may give your correct answer or wrong answer. If you score 95% with your knowledge, the remaining 5% may be due to luck. But 100% can't be by luck. If the question paper is very easy why only 2 students should get 100%. In our intermediate and SSC examination, we are seeing many students scoring 100% even in language subjects also. Here we can say the papers are easy or as per the expectations of the teachers and students.
These days we are seeing many children with very good understanding and maturity. They are able to grasp the subject very fast than many other children. These two guys maybe like that. Their level of understanding may be very high. They might have worked hard with a lot of concentration and focus. We need not underestimate the capability of the students also.