Quadratic Equation And Inequalities

Let \(A = \{ x \in R:[x + 3] + [x + 4] \le 3\} ,\)


\(B = \left\{ {x \in R:{3^x}{{\left( {\sum\limits_{r = 1}^\infty {{3 \over {{{10}^r}}}} } \right)}^{x - 3}} < {3^{ - 3x}}} \right\},\) where [t] denotes greatest integer function. Then,