12.5 years 125 years 125,000 years 125,000,000 years
I gave my students this multiple choice question: A light-year is the measure of how far light can travel in one year. How long has the light from a star 125,000 light-years away been traveling to reach Earth?

Only one answer is correct among these 4 choices:
- 12.5 years
- 125 years
- 125,000 years
- 125,000,000 years

Could you tell me which one is correct?

125,000 years