the I think it's because of better educational and job prospects because in the rural areas people there have poor educational centres and some of the jobs don't give enough payment to support their families so they moved to the Urban areas where they can get better education and better jobs too
The bulk density of a planet will reflect the relative amounts of the materials the world is made of, regardless of what materials occur at the surface.
The length is 88 cm, multiply the width by two and subtract it from the whole perimeter. Then divide the whole perimeter again by two to find the length of one side.
