Answer:
3.122×10¹⁴ g/cm³
Step-by-step explanation:
Diameter of neutron star = 23 km = 2300000 cm
Radius of neutron star = 2300000/2 = 1150000 cm = r
Mass of neutron star = 1.989 × 10³⁰ kg = 1.989 × 10³³ g = m
Volume of neutron star

Density = Mass / Volume

∴ Density of neutron star is 3.122×10¹⁴ g/cm³