PLS HELP FOR ALL MY POINTS ILL GIVE BREAINLEST TO WHO EVER IS RIGHT

I am going by the numbers on the pictures;

1) 2in, 4in, 6in

2) 2ft

3) 4cm

4) 18.55mm and 42.35

5) I am not really sure, if the picture is represented by the 28, the the object would be smaller, if the picture is represented by the 4 the object would be bigger.

Hope this helps a bit