The radioactive isotope $^{60}_{27}Co$ which is used in the treatment of cancer can be made by (n, p) reaction. For this reaction the target nucleus is :-

An (n, p) reaction means the target absorbs a neutron $^{1}_{0}n$ and emits a proton $^{1}_{1}p$.
Target $^{A}_{Z}X + ^{1}_{0}n \rightarrow ^{60}_{27}Co + ^{1}_{1}p$
Balancing mass numbers: $A + 1 = 60 + 1 \Rightarrow A = 60$
Balancing atomic numbers: $Z + 0 = 27 + 1 \Rightarrow Z = 28$
The element with Z = 28 is nickel, so the target is $^{60}_{28}Ni$.
$^{60}_{28}Ni + ^{1}_{0}n \rightarrow ^{60}_{27}Co + ^{1}_{1}p$