In comparison to piperazine, the inductive effect will cause the pKb of methyl-piperazine to be "lower because the electron donating methyl group will make it a stronger base".
methyl-group: electron-giving
the inductive impact with electron-giving make the base more stronger- > lower pKa
The pKb is a proportion of basicity, where a littler pKb value compares to a stronger base.
This electron-giving expands the accessibility of electron charge thickness accessible to give, consequently increasing the quality or strength of N-methyl piperazine to go about as a Lewis base.