Radius of nucleus R=R0A31
Density of nucleus (ρ)=volumeofnucleusMassofnucleus
ρ=34πR3m×A Where m: mass of proton or neutron and A: mass number.
⇒ρ=34πR03Am×A
⇒ρ∝A0
Hence, density of nucleus is independent of mass number.
Therefore, the ratio is 1:1.