Hubble's law states that the velocity with which a galaxy is moving away from the Earth is proportional to:

The angle of maximum elongation for Venus is $47^\circ$. The distance of Venus from the Sun in $AU$ is .......

If a galaxy is at a distance of $430$ million light years from us,what is the Hubble's constant in $km s^{-1}$ per million light years? Its speed is $6.48 \times 10^6 m s^{-1}$.

Which of the planets is the brightest?

The farthest objects in our Universe discovered by modern astronomers are so distant that light emitted by them takes billions of years to reach the Earth. These objects (known as quasars) have many puzzling features,which have not yet been satisfactorily explained. What is the distance in $km$ of a quasar from which light takes $3.0$ billion years to reach us?

$A$ galaxy is observed to be moving with a velocity of $8600 \ km \ s^{-1}$. If it is at a distance of $430$ million light-years from us,the Hubble constant and the corresponding age of the universe are respectively: