A Corporation has the following sales budget for the last six months of 2020:

July	$200,000	October	$180,000
August	160,000	November	200,000
September	220,000	December	188,000

Historically, the cash collection of sales has been as follows:

65 percent of sales collected in the month of sale,

25 percent of sales collected in the month following the sale,

8 percent of sales collected in the second month following the sale, and

2 percent of sales is uncollectible.

What is the ending balance of accounts receivable at the end of September assuming the uncollectible balance is written off in the third month after the sale?

I've seen answers that match similar questions above. Why in problem-solving August sales (160,000*10%) = 16000 September sales (220,000*35%) =777000

Total 93,000

Where did 35% and 10% come from?

Or is there another way to solve the problem?