题干

有7袋米,它们的重量分别是 12、15、17、20、22、24、26公斤.甲先取走一袋,剩下的由乙、丙、丁取走.已知乙和丙取走的重量恰好一样多,而且都是丁取走重量的2倍.那么甲先取走的那一袋的重量是多少公斤?

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答案(点此获取答案解析)

解:由于剩下的由乙、丙、丁三人买走,乙和丙买走的重量恰好相等,都是丁的2倍,

即乙,丙,丁三人买走的重量比为2:2:1,

所以,甲买走一袋后剩下的重量应是2+2+1=5的倍数.

而总重量为:12+15+17+20+22+24+26=136千克,

从136中减去一个数后和得数能被5整除,则这个这个数的个位数字一定是1或者6,

这7袋大米的重量中只有26的个位是6,

所以,甲买走的那一袋大米的重量是26千克.

答:甲买走

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阅读下列短文,从每题所给的四个选项 (A 、B 、C  和 D )中,选出最佳选项。

    A survey has shown that what you do on a plane can be determined by which nationality is listed on your passport.

    According to the results of an international passenger survey, Australians are the biggest drinkers on board with 36 percent choosing to down the hatch, compared to 35 percent of Americans and 33 percent of Brits.

    The Airline Passenger Experience Association(APEX) spoke to around 1,500 people, aged 18 and older, who have travelled by plane at least once during the last three months and were living in the United States, United Kingdom, Germany, Japan, China, Singapore, Australia and Brazil.

    The results found Chinese travelers are most likely to nod off once the seat-belt sign switches off. They are also the first to take out their credit card for some in-flight shopping and the biggest fans of gaming. Americans on the other hand like to use their time in the air more productively---- when not drinking---- choosing to work while flying at 35,000 feet.

    Meanwhile, Brits and Germans are the best at making chat with random strangers----spending 50 percent more time than any other nationality. Comparatively, Brazilians conduct their conversations online via email, messaging apps or social media.

    Despite plane food having a bad reputation, seven out of ten interviewees said they were happy to eat up on the selection of in-flight snacks and meals. In-flight magazines were also popular with four out of five passengers.

    The international flyers did however express their desire for better in-flight entertainment. “The industry has greatly improved the comfort, entertainment and onboard service, and passengers are accepting those improvements” said Russell Lemieux, APEX executive director. “At the same time, passengers are demanding more from their air travel experiences which will drive more improvements touching all aspects of the journey. ” he added.