The farthest objects in out universe discovered by modern astronomeres are so distant that light emitted by them takes billions of year to reach the earth. These object (known as quasers) have may puzzling features, which have yet not been satisfactorily explained. What is the distance in km of a quasar form which light takes 3.0 billion years to reach us?

Explanation

Speed of light, `c= 3xx10^(5)kms^(-1)`
t= 3 billion years `=3xx10^(9)xx365xx24xx60xx60s`
Distance in km,
`d=3xx10^(5)xx3xx10^(9)xx365xx24xx60xx60`
`=9xx365xx24xx36xx10^(16)`
`=2.8xx10^(22)km`.