Ratio of density of nuclear matter to density of water is at least $\left(R_0=1.2\times {10}^{-15} \mathrm{m} \& {\mathrm{m}}_p={\mathrm{m}}_n=1.67\times {10}^{-27} \mathrm{kg}\right)$ 

Assertion (A) : Neutrino is chargeless and possesses spin.

Reason $\left(\mathrm{R}\right):$ Neutrino exists inside the nucleus.