\({R}_{{eq}}={nR}=10 {n}\)

\({i}_{{s}}=\frac{20}{10+10 {n}}=\frac{2}{1+{n}}\)

in parallel

\({R}_{{eq}}=\frac{10}{{n}}\)

\({i}_{{p}}=\frac{20}{\frac{10}{{n}}+10}=\frac{2 {n}}{1+{n}}\)

\(\frac{{i}_{{p}}}{{i}_{{s}}}=20\)

\(\frac{\left(\frac{2 {n}}{1+{n}}\right)}{\left(\frac{2}{1+{n}}\right)}=20\)

\({n}=20\)