What will happen when

a. An egg without shell is placed on a concentrated salt solution for 5 minutes

it will shrink due to exosmosis

Water moves from an area of high solute concentration to an area of low solute concentration. Assuming the salt solution has a greater solute concentration, the water from the inside of the egg will be pulled out into the solution until they become equal in tonicity or 'isotonic'. This will cause the egg to reduce in size.