👨‍👨‍👧‍👦 If a galaxy's overall mass-to-light ratio is 100 solar masses per solar luminosity, and its stars account for only 5 solar masses per solar luminosity, how much of the galaxy's mass must be dark matter?

Question 

If a galaxy's overall mass-to-light ratio is 100 solar masses per solar luminosity, and its stars account for only 5 solar masses per solar luminosity, how much of the galaxy's mass must be dark matter?

Answer

A) 100 percent 

 B) 95 percent
C) 80 percent
D) 50 percent
E) 5 percent