Insufficient information to calculate the updated cash book balance Steps:

• Bank statement balance is $740, but pre-update cash book balance is not provided.
• Record bank charges by subtracting $30 from cash book balance.
• Outstanding cheque of $150 is already deducted in cash book; no adjustment needed for it.
• Cannot compute numerical updated balance without original cash book figure.

Why A is correct:

• Not enough information to confirm; options assume unstated original cash book balance.

Why the others are wrong:

• B. $620: Matches inferred pre-update cash book via reconciliation (bank + outstanding cheque effect adjusted for charges), but question asks for post-update.
• C. $860: Incorrectly subtracts charges from bank + outstanding cheque without proper original cash book.
• D. $890: Adds outstanding cheque to bank statement, overlooking charges adjustment to cash book.

Final answer: Not enough information.