Stinley Co. paid utilities of $145,000 during 2021. At the end of 2021, utilities payable equals $42,000 and utilities expense equals $167,000. What was the balance of utilities payable at the beginning of 2021?

ending amount = beginning amount / (2^n)

where "n" = number of half-lives (or elapsed time / half-life)

ending amount = 50 mg / (2 ^10 / 5.3)

ending amount = 50 mg / (2 ^ 1.8867924528)

ending amount = 50 m / 3.6981210597

ending amount = 13.5203794557 mg

or about 13.5 mg remain

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