Answer questions $18$ and $19$ by running Floyd$$s Algorithm for the All$-$Pairs Shortest$-$Paths

Problem for the weighted graph of question $14-17($nodes a$,$ b$,$ c$,$ d$,$ e$,$ f are numbered as $1,2,3,$

$4,5,6)$

$18.$ What is the length of the shortest path between vertices a and d with intermediate vertices

numbered not higher than $2,$ i$.$e$.,$ at most contains vertex a and b$?$

$[$ A $]3$

$[$ B $]5$

$[$ C $]\backslash$infty

$[$ D $]7$

$[$ E $]9$

$2\mathrm{.}5$

$19.$ What is the length of the shortest path between vertices c and d with intermediate vertices

numbered not higher than $3,$ i$.$e$.,$ at most contains vertices a$,$ b and c$?$

$[$ A $]3$

$[$ B $]6$

$[$ C $]\backslash$infty

$[$ D $]11$

$[$ E $]$