$($b$){\displaystyle \underset{n=1}{\overset{}{}}}(-1{)}^{n-1}\frac{n+1}{n^2}$

$($c$){\displaystyle \underset{n=1}{\overset{}{}}}(-1{)}^n\frac{n^2{2}^n}{3^n}$

please find if these converge conditionally, absolutely$,$ or diverge