Which of these is the main source document for recording cash paid into bank?

The main source document for recording cash paid into a bank is a pay-in-slip. Explanation: When a business or an individual deposits cash into a bank account, a pay-in-slip is filled out to record the transaction. A pay-in-slip is a document provided by the bank that contains information about the account holder, account number, and the amount of cash being deposited. The pay-in-slip also includes a section where the account holder can list the currency denominations of the cash being deposited. The pay-in-slip serves as a source document for recording the cash deposit in the accounting records of the business. It contains information that is used to create a journal entry to record the cash deposit. The journal entry would typically include a debit to the bank account and a credit to the cash account. In contrast, an invoice is a document used to request payment from a customer, while a credit note is a document used to provide a refund or credit to a customer. A cheque book contains blank cheques that are used to make payments from a bank account. These documents are not used to record cash paid into a bank, and thus, are not the main source document for such transactions. Therefore, the correct answer is pay-in-slip.