Which of the following has no solution ?

ANSWER

{x|x<0} and {x|x>0}

EXPLANATION

If the two inequalities have an intersection,then it has a solution.

If the two inequalities have no intersection, then there is no solution.

The inequality {x|x<0} and {x|x>0} has no intersection, there is no solution.

The inequalities

{x|x≤0} and {x|x≥0},

{x|x≤0} or {x|x≥0}

both have intersection, therefore have solutions.