everyone. I encountered this puzzle in a primary school booklet for selective high school exams in Australia. Please help me find out Which of the numbered figures fits into the empty space marked by the question mark, as shown in the picture below. Thanks a lot!
I think the answer is probably
Going from image A to B it looks as though the four symbols on the outside of image A are rotated clockwise 90$^o$ and put into the centre of image B. Similarly, the four symbols at the centre of image A are rotated anti-clockwise 90$^o$ and put on the outside of image B.
The probable next step is to rotate the central symbols of image B 90$^o$ clockwise and put them on the outside of image C and, correspondingly, rotate the outer symbols of image B anti-clockwise and put them in the centre of image C. This corresponds to image 3.
Note here that I have assumed there has been a printing error in image B
View the triangle from the right-angle to the hypotenuse. Swap the contents of the triangle with the square on the left of the hypotenuse (i.e. circle/squiggle, plus/8, triangle/oval, square/square). Rotate the outer square (and the inner square) $45^\circ$ anti-clockwise, and then just the inner square $90^\circ$ clockwise. This gives stage 2.
Swap the contents of the triangles with the contents of the squares on the right of the hypotenuse, rotate the outer + inner square $45^\circ$ clockwise, and the inner square alone $90^\circ$ anti-clockwise. You get 3.