The following events occur for The Underwood Corporation during 2015 and 2016, its first two years of operations.
June 12, 2015	Provide services to customers on account for $35,600.
September 17, 2015	Receive $20,500 from customers on account.
December 31, 2015	Estimate that 45% of accounts receivable at the end of the year will not be received.
March 4, 2016	Provide services to customers on account for $50,600.
May 20, 2016	Receive $10,000 from customers for services provided in 2015.
July 2, 2016	Write off the remaining amounts owed from services provided in 2015.
October 19, 2016	Receive $40,500 from customers for services provided in 2016.
December 31, 2016	Estimate that 45% of accounts receivable at the end of the year will not be received.

I cant not figure out the last one