a, 54 × 275 + 825 × 15 + 275

54 × 275 + 825 × 15 + 275

                  = 54 × 275 + 275 × 3 × 15 + 275 × 1

                  = 54 × 275 + 275 × 45 + 275 × 1

                  = 275 × ( 54+ 45 + 1)

                  = 275 × 100

                  = 27 500