The system of linear equations
$$\lambda $$x + 2y + 2z = 5
2$$\lambda $$x + 3y + 5z = 8
4x + $$\lambda $$y + 6z = 10 has

If $$\alpha $$ and $$\beta $$ be the coefficients of x⁴ and x² respectively in the expansion of
$${\left( {x + \sqrt {{x^2} - 1} } \right)^6} + {\left( {x - \sqrt {{x^2} - 1} } \right)^6}$$, then

Let S be the set of all real roots of the equation,
3^x(3^x – 1) + 2 = |3^x – 1| + |3^x – 2|. Then S :

Let A and B be two events such that the probability that exactly one of them occurs is $${2 \over 5}$$ and the probability that A or B occurs is $${1 \over 2}$$ , then the probability of both of them occur together is :