Both transfer energy. Both require a vacuum. Both have the same speed. Both have the same frequency.
I gave my students this multiple choice question: Which of the following is a similarity 20 between x-ray waves and sound waves?

Only one answer is correct among these 4 choices:
- Both transfer energy.
- Both require a vacuum.
- Both have the same speed.
- Both have the same frequency.

Could you tell me which one is correct?

Both transfer energy.