This question's explanation and your answers so far.
4月1日から5月31日までに，取引①から取引⑤があった。各取引の受注，売上計上，現金回収の状況が表のとおりであるとき，この取引先に対する5月31日時点の売掛金は何万円か。ここで，4月1日時点で売掛金残高はないものとする。
| 取引 | 日付 | 取引内訳 | 金額（万円） | 備考 |
|---|---|---|---|---|
| 取引① | 4月2日 | 受注 | 800 | |
| 4月10日 | 売上計上 | 800 | ||
| 4月30日 | 現金回収 | 800 | ||
| 取引② | 4月5日 | 受注 | 500 | |
| 4月15日 | 売上計上 | 500 | ||
| 4月30日 | 現金回収 | 500 | ||
| 取引③ | 5月1日 | 受注 | 1,300 | 6月30日 回収予定 |
| 5月10日 | 売上計上 | 1,300 | ||
| 取引④ | 5月6日 | 受注 | 1,000 | 回収予定日未定 |
| 5月15日 | 売上計上 | 1,000 | ||
| 取引⑤ | 5月20日 | 受注 | 400 |
1,000 counts only transaction ④. In addition to transaction ④'s 1,000, transaction ③'s 1,300, whose sales were recorded on May 10 and whose collection is scheduled for Jun 30, is also uncollected accounts receivable as of May 31, and this option fails to add it.
1,400 can be regarded as transaction ④'s 1,000 plus transaction ⑤'s 400. Transaction ⑤ was only an order received on May 20, with no sales recorded, so it does not constitute accounts receivable. This option also overlooks transaction ③'s 1,300, whose collection is scheduled for Jun 30.
正解 Accounts receivable is the amount that has been recorded as sales (revenue recognized) but for which cash has not yet been collected. Look at the status of each transaction as of May 31. Transaction ① (8,000,000 yen) was collected in cash on Apr 30, and transaction ② (5,000,000 yen) was also collected in cash on Apr 30, so both have a balance of 0. Transaction ③ (13,000,000 yen) had its sales recorded on May 10, but collection is scheduled for Jun 30, so as of May 31 it is still uncollected and is accounts receivable. Transaction ④ (10,000,000 yen) also had its sales recorded on May 15, and its collection date is undetermined, so it too is uncollected accounts receivable. Transaction ⑤ (4,000,000 yen) was only an order received on May 20, with no sales recorded, so it is not yet accounts receivable. Therefore accounts receivable is the sum of transactions ③ and ④, namely 1,300+1,000 = 2,300 (in units of 10,000 yen), and the correct answer is “ウ”.
2,700 adds transaction ⑤'s 400 on top of the correct answer of 2,300. Transaction ⑤ is only an order received, with no sales recorded yet, so it is not included in accounts receivable. Note that an order received does not mean sales recorded.