Let A = {x $$ \in $$ R : x is not a positive integer}.

Define a function $$f$$ : A $$ \to $$  R   as  $$f(x)$$ = $${{2x} \over {x - 1}}$$,

then $$f$$ is :

The number of all possible positive integral values of $$\alpha $$  for which the roots of the quadratic equation, 6x² $$-$$ 11x + $$\alpha $$ = 0 are rational numbers is :

If the circles

x² + y² $$-$$ 16x $$-$$ 20y + 164 = r²  

and  (x $$-$$ 4)² + (y $$-$$ 7)² = 36

intersect at two distinct points, then :

An urn contains 5 red and 2 green balls. A ball is drawn at random from the urn. If the drawn ball is green, then a red ball is added to the urn and if the drawn ball is red, then a green ball is added to the urn; the original ball is not returned to the urn. Now, a second ball is drawn at random from it. The probability that the second ball is red, is :