Given data:
- Thickness of the silvered glass slab (t) = 6 cm
- Distance of the object from the slab (u) = 28 cm
- Refractive index of the silvered glass (n) = 1.5

Calculating the position of the final image:

Step 1: Finding the position of the first image
The object is placed in front of the silvered glass slab, and the light rays coming from the object will undergo refraction at the first surface of the slab.

Using the lens formula, we can find the position of the first image:

1/f = 1/v - 1/u

Since the object is placed at infinity (u = ∞), the equation becomes:

1/f = 1/v

As the refractive index of the medium in front of the slab is air (n = 1), the focal length of the slab can be calculated as:

f = (n - 1) * t

Plugging in the values, we get:

f = (1.5 - 1) * 6
= 0.5 * 6
= 3 cm

Using the lens formula, we can find the position of the first image:

1/3 = 1/v

Simplifying, we get:

v = 3 cm

Therefore, the position of the first image is 3 cm from the first surface of the slab.

Step 2: Finding the position of the final image
The light rays from the first image will reflect from the silvered surface of the slab and then undergo refraction again at the second surface of the slab.

Since the light rays are reflecting from the silvered surface, the angle of incidence and the angle of reflection will be the same. Therefore, the reflected rays will retrace their path.

As a result, the light rays will pass through the first surface of the slab again and converge at the position of the first image. Hence, the position of the final image will be the same as the position of the first image.

Therefore, the position of the final image is 3 cm from the first surface of the slab.

Summary:
- The position of the first image is 3 cm from the first surface of the slab.
- The position of the final image is also 3 cm from the first surface of the slab.