This question likely refers to the number of independent equations obtained using Nodal Analysis In nodal analysis, we apply Kirchhoff's Current Law (KCL) to the nodes of a circuit to determine the node voltages If a circuit has 'N' nodes in total, one node is typically chosen as the reference node (ground, potential = 0 V) KCL equations are then written for the remaining (N-1) non-reference nodes These (N-1) equations form a set of independent equations that can be solved for the unknown node voltages
Given N = 10 nodes, the number of independent nodal equations is N - 1 = 10 - 1 = 9