Cost of Goods Sold or Sales

If there is no profit, then it will be equal to cost of good sold and  when there is profit, then it will be equal tosales ...

simple

Hi, I’m new to accounting and trying to solve a text book problem. Can anyone help me in understanding how the author calculated purchase (36,000) in Cost of goods sold?

Question: 

Direct labor cost 16,000

Cost of goods sold 56,000

Opening and Closing Balances

Raw Material                        8,000    8,600

Work-in-progress                                 8000    12,000

Finished goods                    14,000   18,000

Selling expenses                                 3,400

General Admin                    2,600

Sales for the month            75,000

Solution given:

A)    Sales (given)                                                                                        75,000

B)    Cost of goods sold:

                Raw Materials Consumed:

                                Opening stock (given)                        8,000

                                Purchase (balancing figure)             36,000

                                                                                                44,000

                                Closing stock                                        (8,600)   35,400