Help with rectification of errors problem

WRONG ENTRY = RAMA/C ---------------------------DR

                                             TO SALE

                                   PURCHASE A/C ----------------DR

                                              TO RAM

RECTIFY ENTRY = PURCHASE A/C                          DR    1000

                                              TO SALE                                                                  1000

usually entry for posting on sales account is to give debit to customer and give credit to sales account. entry posting for purchase account is to credit the customer and debit the purchases account. purchase account is a asset account and hence posting the debit increases the number of purchases by 1000 which has to be decreased and sales account which is revenue account which is not posted should be increased by the amount of sales which can be done by crediting the sales account by the number of the sales. finally the customer who was credited 1000 instead of being debited 1000 (Its like saying you brought goods from me so I owe you 1000 rupees for the goods brought from me!! so first we have reduce what we owe to him by 1000 and then say that he owes us 1000) thus you debit the customer with 2000

original entries(wrong entries)

purcases Dr. 1000    ----

Ram A/c -------          1000

correcting entries

(first reverse the wrong entry)

Ram A/c  Dr. 1000    ----

purcases -------          1000

The we write the entry which is ommitted (record sales)

Ram A/c  Dr. 1000    ----

sales -------          1000

the compound entry combining both is

Ram A/c  Dr. 2000    ----

purcases -------          1000

sales -------                1000

But tejas and swati these are before prepartion of trial balance.....so noritification form of entry is used in it.

help me with understanding this question What question is saying...... i haven't understand the question what question is saying (use ledger with imaginary figures to help me learn)

Once again this Question is before prepartion of trial balance.