JEE Main PAPER - 1

For each $t \in \mathbb{R}$  , let [t] be the greatest integer less than or equal to $t$  . Then $\lim_{x \to 0^+} x \left(\left[ \frac{1}{x} \right] + \left[ \frac{2}{x} \right] + \dots + \left[ \frac{15}{x} \right]\right)$  :