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guo573874201

1. From May 1 to May 30 in the same year, the balance in a checking account increased.What was the balance in the checking account on May 30 ?
(1)If, during this period of time, the increase in the balance in the checking account had been 12 percent, then the balance in the account on May 30 would have been $504.
(2)During this period of time, the increase in the balance in the checking account was 8 percent.答案选C  为什么呢  我没又看懂题  为什么出来了两个增长率呢

2.Last year in a group of 30 businesses, 21 reported a net profit and 15 had investments in foreign markets.How many of the businesses did not report a net profit nor invest in foreign markets last year?
(1)Last year 12 of the 30 businesses reported a net profit and had investments in foreign markets.
(2)Last year 24 of the 30 businesses reported a net profit or invested in foreign markets, or both.答案选D  第二个条件是怎么推出来的呢？

3.If x, y, and z are consecutive even positive integers, which of the following could be equal to x + y + z ?

A.141
B.200
C.318答案选C  怎么得出的啊
D.391
E.412

guo573874201

我只是纳闷第二题的第二个条件 30中的24给出了 3个可能性， 所以不确定  是我的理解的问题吗   请问能帮我翻译一下马  谢了