Use the Excel output below to answer the question that follows.

How many racks are used?

$\backslash$table$[[$Cell$,$Name,$\backslash$table$[[$Final$],[$Value$]],\backslash$table$[[$Reduced$],[$Cost$]],\backslash$table$[[$Objective$],[$Coefficient$]],\backslash$table$[[$Allowable$],[$Increase$]],\backslash$table$[[$Allowable$],[$Decrease$]]],[$SBS$18,\backslash$table$[[$Umbrellas$],[$Women$]],12,0,4,1,2\mathrm{.}5],[$$$C$$$18,\backslash$table$[[$Umbrellas$],[$Golf$]],0,-0\mathrm{.}5,6,0\mathrm{.}5,1E+30$