An unpolarized light of certain intensity passes through a combination of two polarizers whose transmission axes are at 30° and 90°, respectively,…

An unpolarized light of certain intensity passes through a combination of two polarizers whose transmission axes are at $\displaystyle 30$° and $\displaystyle 90$°, respectively, with respect to the horizontal axis. A third polarizer with its transmission axis at $\displaystyle 60^{\circ}$ with the horizontal axis is placed between the two existing polarizers. The ratio of the output intensities with and without the third polarizer is $\displaystyle \_\_\_\_$.