  MIN     0.55 X1 + 0.42 X2 + 0.38 X3   
  st
         25 X1 +  45 X2 +  32 X3 >=    35  ! Protein constraint
         11 X1 +  10 X2 +   7 X3 >=     8  ! Min Fat constraint
         11 X1 +  10 X2 +   7 X3 <=    10  ! Max Fat constraint
        235 X1 + 160 X2 + 190 X3 >=   180  ! Vitamin A constraint
         12 X1 +   6 X2 +  10 X3 >=     9  ! Vitamin B constraint
            X1 +     X2 +     X3  =     1  ! total wt of mixture
  END