The number of real solutions of the equation $${x^2} - 3\left| x \right| + 2 = 0$$ is

The real number $$x$$ when added to its inverse gives the minimum sum at $$x$$ equal :

If $$x$$ is positive, the first negative term in the expansion of $${\left( {1 + x} \right)^{27/5}}$$ is

A student is to answer 10 out of 13 questions in an examination such that he must choose at least 4 from the first five questions. The number of choices available to him is