Chemistry help please?

e.
One might expect that the volumes are additive, i.e.
New volume = (50 mL) + (30 mL) = 80 mL

f.
The actual volume is smaller than the expected volume. This can be explained that the some smaller water molecules occupy the empty spaces between the larger ethanol molecules, leading to a decrease in volume.

e. you Might expect that the volumes are additive, so that the volume would be 80 mL
f. Obviously, the two volumes are not additive. As the solution forms, the volume of the solution is less than the two volumes used.

55mL, the polarity of ethanol and water makes them near completely miscible