Difference between list of balance and ledger control account

I had this question following: At 1 April 20X9, the payables ledger control account showed a balance of $142,320 At the end of April, the following totals are extracted from the subsidiary book for April Purchase day book 183,800 Returns outwards day book 27,490 Return inwards day book 13,240 Payments to payables after deducting $1,430 cash discount 196,360 It is also discovered that: (a) The purchase day book figure is net of sales tax at 17.5%, the other figures all include sales tax (b) A customer's balance of 2420 has been offset against his balance of 3650 in the payables ledger (c) A supplier's account in payables ledger, with a debit balance of 800 has been include the list of payables as credit balance What is the corrected balance on the payables ledger control a/c? I wondered that why the amount of 800 in payables of list of payable balance didn't entered in the payables ledger account? Could you explain that and give me the fastest way to settle other question like this?