Insufficient information to calculate total expenses Steps:

• Identify cash expenses as $42,000.
• Calculate required provision as 2% of $25,000 trade receivables =$500.
• Note "depreciation for doubtful debts" $4,200 is ambiguous (possible opening provision, write-offs, or expense, but date and term conflict).
• Recognize reducing balance method for provision is unclear without opening receivables/provision or write-offs; cannot determine adjustment to $500.

Not enough information.

Final answer: Not enough information.