Consider an undirected $($positively$)$ weighted graph G $=($V$,$ E$)$ with a MST T and a shortest path

$\backslash$pi $($s$,$ t$)$ between two vertices s$,$ t in V$.$ Find whether T will still be an MST and $\backslash$pi $($s$,$ t$)$ be a shortest

path if

$($a$)$ Weight of each edge is multiplied by a fixed constant c $>0.$

$($b$)$ Weight of each edge is incremented by a fixed constant c $>0.$

Explain your answers