The following is an aging schedule for a companys accounts receivable as at December 31, 2019:

						Number of days past due
	Customer's name	Total amount owed		Current (not yet due)		130		3160		6190		Over 90
	Aber	$32,000				$9,000		$23,000
	Bohr	46,000		$46,000
	Chow	52,000		15,000		22,000				$15,000
	Datz	22,000										$22,000
	Others	158,000		95,000		15,000		13,000		15,000		20,000
		$310,000		$156,000		$46,000		$36,000		$30,000		$42,000
	Estimated percentage that will be uncollectible			3%		6%		10%		25%		50%
	Estimated value of uncollectibles	$39,540		$4,680		$2,760		$3,600		$7,500		$21,000

On December 31, 2019, the unadjusted balance in the Allowance for Doubtful Accounts (prior to the aging analysis) was a credit of $16,000.

a. Journalize the adjusting entry for bad debts on December 31, 2019

b. Journalize the following selected events and transactions in 2020:

i.	On March 1, an $1,100 customer account that originated in 2020 is judged uncollectible.
ii	On September 1, an $1,100 cheque is received from the customer whose account was written off as uncollectible on March 1.

c. Journalize the adjusting entry for bad debts on December 31, 2020, assuming that the unadjusted balance in Allowance for Doubtful Accounts at that time is a debit of $1,000 and an aging schedule indicates that the estimated value of uncollectibles is $36,500.