data one;
   wtpanacea=0.3;    wtichor=0.2;    wtgold=2.0;
   volpanacea=0.025; volichor=0.015; volgold=0.002;
   valpanacea=3000;  valichor=1800;  valgold=2500;
   maxwt=25; maxvol=0.25;

   /* we can prune the possible selections */
   maxpanacea = floor(min(maxwt/wtpanacea, maxvol/volpanacea));
   maxichor = floor(min(maxwt/wtichor, maxvol/volichor));
   maxgold = floor(min(maxwt/wtgold, maxvol/volgold));
   do i1 = 0 to maxpanacea;
      do i2 = 0 to maxichor;
         do i3 = 0 to maxgold;
            panacea = i1; ichor=i2; gold=i3; output;
         end;
      end;
   end;
run;
data one; set one;
   vals = valpanacea*panacea + valichor*ichor + valgold*gold;
   totalweight = wtpanacea*panacea + wtichor*ichor + wtgold*gold;
   totalvolume = volpanacea*panacea + volichor*ichor + volgold*gold;
   if (totalweight le maxwt) and (totalvolume le maxvol);
run;
proc sort data=one;
   by descending vals;
run;
proc print data=one (obs=4);
   var panacea ichor gold vals;
run;