In the sequence of tiles shown below, the missing tile indicated by the question mark should be

To solve the problem, we need to identify the pattern in the sequence of tiles shown in the images. Let's analyze the sequence step by step:
Continuing the sequence from the last part:
The sequence is forming a natural progression, where each next tile has one additional dot than the previous one. Considering this, the missing tile should naturally contain 3 dots.
The correct image based on this logic, where the missing tile should have 3 dots, matches the option provided as the correct answer:

An opaque cylinder (shown below) is suspended in the path of a parallel beam of light, such that its shadow is cast on a screen oriented perpendicular to the direction of the light beam. The cylinder can be reoriented in any direction within the light beam. Under these conditions, which one of the shadows P, Q, R, and S is NOT possible?
How many triangles are present in the given figure?


A block with a trapezoidal cross-section is placed over a block with rectangular cross section as shown above.
Which one of the following is the correct drawing of the view of the 3D object as viewed in the direction indicated by an arrow in the above figure?
An opaque pyramid (shown below), with a square base and isosceles faces, is suspended in the path of a parallel beam of light, such that its shadow is cast on a screen oriented perpendicular to the direction of the light beam. The pyramid can be reoriented in any direction within the light beam. Under these conditions, which one of the shadows P, Q, R, and S is NOT possible?

Five cubes of identical size and another smaller cube are assembled as shown in Figure A. If viewed from direction X, the planar image of the assembly appears as Figure B. 
If viewed from direction Y, the planar image of the assembly (Figure A) will appear as