Cardboard comes in different weights, depending on thickness, whether it is corrogated (i.e. with spaces), pressed, etc. So, the answer would depend first on the type and weight of the cardboard.
Regardless of type of cardboard or the weight of the type, I would guess it would weigh far less than the CD and CD case together.
I would further guess it would weigh about or less than the plastic CD case without the CD, with both CD and and extra cardboard piece being the same dimensions (height+width) and if the cardboard was thin.
Lifes
It has 156 cubic inches
Rocks vary greatly in density and weight. A piece of pumice that size could weigh maybe an ounce, while a lead-laden rock may weigh many times that, maybe closer to a pound.
Impossible to answer !... the size of a person's shoes has no bearing on how much they weigh.
Depends on size
well it really depends on the size of the 5 year old
Depends on the size and quality of the paper.
Not enough information to answer.... There is no 'standard' weight for cardboard. A box with walls of 4mm thickness will weigh less than the same size box, with walls of 6mm thickness.
It has 156 cubic inches
its has higher density
How long is a piece of string? You have provided no size and density information, so the question is unanswerable.
Gold
You can weigh any size.
to start you get a round piece of cardboard and a circular piece of paper and glue together then get a pin puncture just under the paper and back up again on the other side of the cardboard get another piece of paper the same size and colour in you can also get wrapping paper if you preferred glue on and you have YOUR OWN BADGE!
I am a size 4 dress size and weigh around 120.
They weigh differently depending on what size the egg it is.
Probally about 300
How much do the female reproductive organs weigh?