Receivables control ledger

The following question has been asked in my model ACCA exams and shows only the right and wrong answer… It doesn’t show how the answer is obtained.

Q)On 31 March Olsen Ltd had a balance of $62,840 on its receivables control account, compared to a total balance of $61,910 on the receivables ledger. Upon investigation it was discovered that:

I. Late payment interest charged to customers on overdue amounts of $410 had not been recorded in the nominal ledger

II. The balance on H Duck’s account of $390 had been omitted from the total of balances in the receivables ledger

III. Sales returns of $825 had been treated as purchase returns in the nominal ledger

In addition, the company decided to write off $150 in relation to an irrecoverable debt at the
month end

What was the corrected balance on the receivables control account at 31 March?

a) $61,450

b) $61,455

c) $62,275

d) $62,665

The answer I got is a) $61450 which is obtained by adding $410 [Dr] , deducting $150 [Cr] and accounting for sales return by eliminating the wrong purchase return and accounting for sales returns by subtracting $825 two times, ie; $1650 to/(from) the opening balance of $62840.

But the right answer shown is c) $62275. Can you please explain how the right answer is obtained.

Thanks in advance.