Hint: To answer this question, we first need to understand that a mirror would both reflect and refract an image and In theory, an object positioned off center between two parallel mirrors may generate an infinite number of images.
Complete answer: As discussed above two images will be formed by the thick mirror. The first image due to reflection will be very dim as very low light is reflected. When an image is held at a close distance from the mirror, it appears clearer. The first image that comes to mind is When held in the center of a parallel mirror, it produces the closest image.
And also, the second image will be formed by the refracted light which is further reflected by the back silver surface of the mirror but this image formed is the brightest among all the images formed as the rest of the images will be very dim.
Note:A reflective coating is applied to the back of plane mirrors. The glass surface of the mirror reflects some of the light that falls on it. A portion of it passes through the glass layer, is refracted, is mirrored at the other end, travels to the first surface, is refracted again, and moves away from the mirror.