I am doing my research on Apple Inc. using this link below

https://www.sec.gov/ix?doc=/Archives/edgar/data/320193/000032019319000119/a10-k20199282019.htm

1. Calculate and compare your selected corporation's cash ratio to its biggest competitor for the two years preceding the current year. Show your calculations.
2. What was the amount of Accounts Receivable (A/R) for the two years preceding the current year?
3. What was the amount for Allowance for Doubtful Accounts for year end in both of the two years preceding the current year?