At a local store, the numbers of gallons of skim milk, 2% milk, and whole milk sold over the weekend are represented by a matrix A.

 At a local store, the numbers of gallons of skim milk, 2% milk, and whole milk sold over the weekend are represented by a matrix A.                               Skim               2%         Whole     

                  Friday       40              64                52

              Saturday      60              82                76

                Sunday       76              96                84

The selling prices per gallon and the profits per gallon for the three types of milk are represented by B.

                         Selling price        Profit

         Skim                  $3.45      $1.20

             2%                 $3.65      $1.30

        Whole                $3.85      $1.45

 a) Compute AB and interpret the result.

 b) Find the store's total profit from milk sales for the weekend