Question

It can be inferred from information presented in the passage that if the density of the universe were equivalent to significantly less than three hydrogen atoms per cubic meter, which of the following would be true as a consequence?

• A. Luminosity would be a true indicator of mass.
• B. Different regions in spiral galaxies would rotate at the same velocity.
• C. The universe would continue to expand indefinitely.
• D. The density of the invisible matter in the universe would have to be more than 70 times the density of the luminous matter.
• E. More of the invisible matter in spiral galaxies would have to be located in their nuclei than in their outer regions.

Answer 1

The correct option is D The density of the invisible matter in the universe would have to be more than 70 times the density of the luminous matter.

The correct answer for this would be option D, i.e., the density of the invisible matter in the universe would have to exceed that of the luminous by 70 times. The passage explains that the expansion of the galaxy is identified with the luminosity of the matter therein, for which to shine, the invisible dark matter is necessary to exist in higher density. The statements of options A,B,C and E are not supported by the text, hence, they are incorrect.