Galaxy a has 5x10^23 stars
Galaxy b has 9x10^27 stars
Choose which galaxy has more stars and how many times more stars than the other galaxy
Galaxy b has more stars than Galaxy a.
To determine how many times more stars Galaxy b has than Galaxy a, we can divide the number of stars in Galaxy b by the number of stars in Galaxy a:
Number of stars in Galaxy b / Number of stars in Galaxy a
(9x10^27) / (5x10^23)
9/5 x (10^27 / 10^23)
1.8 x 10^(27-23)
1.8 x 10^4
Therefore, Galaxy b has 18,000 times more stars than Galaxy a.