Microsoft Corporation develops, produces, and markets a wide range of computer software including the Windows operating system. Microsoft reported the following information about Net Sales Revenue and Accounts Receivable (all amounts in millions). June 30, 2016 June 30, 2015
Accounts Receivable, Net of Allowance for Doubtful Accounts of $430 and $330 $18,300 $17,900
Net Revenues 85,320 93,580

According to its Form 10-K, Microsoft recorded Bad Debt Expense of $150 and did not recover any previously written-off accounts during the year ended June 30, 2016.

Required:
a. What amount of accounts recelvable was written off-during the year ended June 30. 2016?
b. What was Microsoft's receivables turnover ratio in 2016?