AMC 8 2015 Problem 9
AMC8 2015 年第 9 题
数列与规律★★☆☆☆
On her first day of work, Janabel sold one widget. On day two, she sold three widgets. On day three, she sold five widgets, and on each succeeding day, she sold two more widgets than she had sold on the previous day. How many widgets in total had Janabel sold after working 20 days?
在她上班的第一天卖出了 1 个器具，第二天卖出了 3 个器具，第三天卖出了 5 个器具，且在往后的每一天，她都比前一天多卖出 2 个器具，那么当她工作了 20 天后，共卖出多少个器具？
- A.39
- B.40
- C.210
- D.400
- E.401
正确答案 · Correct Answer
D
解析 · Solution
解析整理中
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