Help with rectification of errors problem

Q2. Bills Receivable from Mr. A of Rs.500 was posted to the credit of the Bills Payable Account and also credited to A account.?(before prop. of trial balance)

Ans."To wrong posting on Rs. 500" in the debit of bills payable account and also "To omission of posting on Rs. 500 in the debit of Bills Receivable account"

Explain me the Question and also the wrong part (with the help of ledger first the wrong part then the right part)

thanks in Advance

Note:  I am a beginner in Accounts so plz help me

wrong entry =1). BR A\C --------------------DR                   

                                   TO A A\C

                          2). BP A\C -------------------DR 

                                            TO A A\C

REVERSE OF WRONG ENTRY = A A\C -----DR

                                                                 TO BR A\C

                                                                 TO BP A\C

CORRECT ENTRY= BR A\C -------------------DR

                                                  TO A A\C

                                      A A\C----------------------------------DR  

                                                        TO BP A\C

RECTIFYING ENTRY = BR A\C ------------------------DR    500

                                                            TO BP A\C                                         500

when a bill of exchage is recorded, bills receivable is debited and the accepted party account is credited. In the entry the accepting party is credited correctly but bills payable account is credited. so we have to first reverse the entry of bill payable by debiting bills payable by 500 and debit bills receivable ( which is ommitted) by 500