3 problems

Let $T_n$ be the triangular grid graph shown in Figure, with $n$ rows and $m=n^2$ cells. Let $a$ and $b$ be distinct vertices of degree $2$, and let $r_n(a,b)$ be the resistance di…

Let $G$ be the block tower graph $C_4\square P_n$, the Cartesian product of the $4$-cycle and the path of length $n$, with $4n$ vertices, and let $H$ be the block tower graph…

Let $G$ be the straight linear $K$-tree with $n$ vertices and parameter $k\geq 1$, and let $H$ be the straight linear $K$-tree with $n+1$ vertices. Write $r_G(u,v)$ for the resista…