The following information is available regarding the ending balances of the accounts of a company called Certified Carbon Inc. on December 31 before the adjusting entries have been made:

Cash = $12,600

Accounts Receivable = $1,250

Office Supplies = $180

Prepaid Insurance = $240

Office Equipment = $3,400 and Accumulated depreciation office equipment = $600

Accounts Payable = $700

Unearned Revenue = $460

Common Stock = $2,000

Retained Earnings = $2,870

Dividends = $400

Certified Carbon Revenue = $2,900

Wages Expense = $1,500

Rent Expense = $400

a) Determine the value of the closing balance of Prepaid insurance after the following adjusting entry: Insurance that expired during December was $40

b) Determine the adjusting entry for the following transaction: Depreciation for Office Equipment for December totaled $100

c) Determine the adjusting entry for the following transaction: Revenues earned for services performed in December but not billed by the end of the month totaled $300

d) Determine the ending balance for Wages Expense if the Unpaid wages on December 31 totaled $300