Solution :
The total number of ways in which numbers can be choosed = 25*25 = 625
The number of ways in which either players can choose same numbers = 25
\(\therefore\) Probability that they win a prize = \(25\over 625\) = \(1\over 25\)
Thus, the probability that they will not win a prize in a single trial = 1 – \(1\over 25\) = \(24\over 25\)