Gunflint Adventures operates an airplane service that takes fishing parties to a remote lake resort in northern Manitoba, Canada. Individuals must purchase their tickets at least one month in advance during the busy summer season. The company adjusts its accounts only once each month. Selected balances appearing in the company's June $30$ adjusted trial balance appear as follows: Debit Credit Prepaid airport rent $ $12,000$ Prepaid insurance $5,250$ Airplane $360,000$ Accumulated depreciation: airplane $ $150,000$ Unearned passenger revenue $90,000$ Other Information The airplane is being depreciated over a $12-$year life with no residual value. Unearned passenger revenue represents advance ticket sales for bookings in July and August at $$500$ per ticket. Six months' airport rent had been prepaid on May $1.$ The Prepaid insurance is what remains of a $12-$month policy purchased on February $1.$ Passenger revenue earned in June totaled $$60,000.$ Required: Determine the following: The age of the airplane in months. The monthly airport rent expense. The amount paid for the $12-$month insurance policy on February $1.$ Prepare the adjusting entries made on June $30$ involving the following accounts: Depreciation expense: Airplane Airport rent expense Insurance expense Passenger revenue earned