This question is about finding the odd one. My question is what is the answer and what is the reason behind it. Also, how should we approach such questions.
The third is the odd one out. All three arrows curve the same way in this image whereas they curve different directions on 1, 2 and 4. Also, the top arrow curves towards the other arrows but in 1, 2 and 4 the top arrow curves away from the others.
Puzzle 2 and 3:
The reason is the same in these two puzzles. In puzzle 2 it is the second image which is different and in puzzle 3 it is the fourth image. The reason is that the odd-image out is a rotation plus mirror transformation whereas the other three are just rotations.
The third one, as it is the only one where all the arrows face the same way, the others the one on top faces a different direction from the rest
The second, the flower is on the left of the stem
The fourth, the spiral goes left out from the centre
To do this, I look for a common link and see if there is a picture without the link
Just to add to the "Also, how should we approach such questions" part of your question, my first instinct upon seeing the puzzle was to notice that all four circles in each set appeared to be rotations of each other. Because the question asked for the 'odd one out', that gave me a hint that perhaps one of the circles, despite appearing to be the same as the others, was not the same. It then became a simple exercise of identifying which one was different.
3rd picture. All the rest can be seen as a clockwise rotation of the other images. The 3rd one doesn't. Also it has three arrows in same pattern
2nd picture. All the rest can be seen as a clockwise rotation of the other images. The 2nd one is a mirror image of one of the rotations.
4th picture. All the rest can be seen as a clockwise rotation of the other images. The 4th one is a mirror image of one of the rotations.
Rotating an image in clockwise direction brings the other three images. While the odd one is a mirror of one of the clockwise rotated images.