$-8\mathrm{.}5$ Subway, with more than $20,000$ outlets in the U$.$S$.,$ is planning for a new restaurant in Buffalo, New York. Three locations are being considered. The following table gives the factors for each site.

$\backslash$table$[[$FACTOR$,$WEIGHT,MAITLAND,BAPTIST CHURCH,NORTHSIDE MALL$],[$Space$,30,60,70,80],[$Costs$,25,40,80,30],[$Traffic density,$20,50,80,60],[$Neighborhood income,$15,50,70,40],[$Zoning laws,$10,80,20,90]]$

a$.$ At which site should Subway open the new restaurant?

b$.$ If the weights for Space and Traffic density are reversed, how would this affect the decision?