A radioactive nucleus emits 3 alpha particles and 2 positrons. For the resultant nucleus, the ratio of neutrons to protons is (consider the initial nucleus to have atomic number Z and atomic mass A):
1
(A – Z - 4) / (Z - 8)
2
(A – Z - 12) / (Z - 4)
3
(A – Z - 8) / (Z - 4)
4
(A – Z - 4) / (Z - 2)