If 15 mL of olive oil, 30 mL of ethanol, and 55 mL of distilled water were
poured into a 100 ml beaker, in which order would the liquids layer from top
to bottom?

the 30mL of ethanol would be in the top because it is the most light fluid out of all three. It has the lowest density

The 15mL of olive oil would be in the centre because it is less dense than water but more dense than ethanol

The 55mL of distilled water will be in the bottom because it is more dense

wavelength divides in half and speed stays the same.