Two plane mirrors are inclined at an angle of $60^\circ$. The number of images of a point object placed between them is:

When $360^\circ/\theta$ is an integer, the number of images is $n = \dfrac{360^\circ}{\theta} - 1$. Here $360^\circ/60^\circ = 6$, an integer, so $n = 6 - 1 = 5$.