The probability that a relation R from {x, y} to {x, y} is both symmetric and transitive, is equal to :

The probability that a randomly chosen 2 $$\times$$ 2 matrix with all the entries from the set of first 10 primes, is singular, is equal to :

The probability that a randomly chosen one-one function from the set {a, b, c, d} to the set {1, 2, 3, 4, 5} satisfies f(a) + 2f(b) $$-$$ f(c) = f(d) is :

The probability, that in a randomly selected 3-digit number at least two digits are odd, is :