A draft statement of cash flows contains the following calculation of cash flows from operating activities:

                                                                                            $m

Profit before tax                                                                   13

Depreciation                                                                         2

Decrease in inventories                                                       (3)

Decrease in trade and other receivables                              5

Decrease in trade payables                                                  4

Net cash inflow from operating activities                              21

Which of the following corrections need to be made to the calculation?

1 Depreciation should be deducted, not added.

2 Decrease in inventories should be added, not deducted.

3 Decrease in receivables should be deducted, not added.

4 Decrease in payables should be deducted, not added