The total number of possible pairs of selected numbers = N = 25 × 25 = 625.
If the numbers match, then both the numbers should be (1, 1), (2, 2), ... and so on.
Let's say that A is the event that both the selected numbers match.
The number of possible cases where the numbers match = n(A) = 25.
And.
P(A)===.
∴ Probability that the numbers will not match
=1−P(A)= Hence, the probability of not winning a prize is
.