Which of the following, if true of the United States in the period 1978 to 1988, most helps to account for the finding?
【选项】Glass bottles are significantly heavier than aluminum cans of comparable size.
重量百分比是g/t,a/t.重量百分比下降的多,说明玻璃在变少。玻璃的重量一直都是不变的,数量的多少会决定它在总体垃圾中占的百分比。因为玻璃收集的不如铝广泛,但却又比铝下降的多,那么肯定还有别的措施导致玻璃量的减少。铝的重量比下降的慢,证明铝的数量下降的慢。因为现在要做的对比是现在比以前下降的量。玻璃和铝的数量一直都是固定不变的,那么如果想要重量在total中占得百分比变少,就得把数量往低了降。 我的错误思路:我想的是虽然玻璃回收的数量不如铝多,但玻璃的重量如果比铝重,那么就有可能回收的总重量超过铝。但是,原文进行的比较是,它们各自的重量占总重量的百分比的下降。
问的是percentage
这个可能是对的 但是文中已经说了循环铝罐更加的流行 所以一定要找positive solved answer
实际中回收铝更广泛,但是在垃圾中,玻璃瓶比铝减少了更多百分比,一开始没看到percentage,想应该是玻璃重,尽管没几个但是可能总重量减少的多,后来看percentage就不对了,除下来应该与本身没关系。所以就是一些工厂不用玻璃了,改塑料,那么今年垃圾中玻璃就少的厉害了
• ... more aluminum than glass (percentage-wise) is being removed from the trash -- for recycling purposes, BUT • ... nevertheless, the weight of glass went down by a greater percentage. these are clearly in conflict with each other, so, we need some other reason why the weight of glass went down -- above and beyond recyclin
Ron: this problem turns on the differences between PERCENTAGES and ABSOLUTE NUMBERS. facts: * the PERCENTAGE of recycled aluminum was higher than the PERCENTAGE of recycled glass. this is what it means when we say that aluminum recycling was more widely practiced. BUT * the NUMERICAL CHANGE in aluminum in the trash was lower than the NUMERICAL CHANGE in glass in the trash. if all the stuff missing from the trash had been recycled, this would be impossible. therefore, we need another explanation, besides recycling, for WHY THE TOTAL USE OF GLASS HAS GONE DOWN. that's the only way that these findings are mathematically possible. the problem quotes two separate percentages -- one percentage of the total weight of glass, and another percentage of the total weight of plastic. because these are separate percentages, it doesn't matter how much each thing weighs. for instance, if a household uses half as many glass containers, then that's a 50% reduction, regardless of whether the glass containers weigh 2 ounces or 2 tons each. if the problem were talking about the relative contributions of glass and plastic to the total weight of all recycled materials, then you would have a point here. however, the problem isn't talking about that.
应该比较的是 相对比重的变化 你提到重量的话 就是在考虑绝对重量的变化 感觉要找一个变量,一个诱因导致这个结果 但是重量这个事情,是恒定的。之前之后都是玻璃瓶更重。 前后都没变,那么不应该是一个诱因。
首先要记住这种答案的逻辑永远不是gmat需要的。
decline by Percentage , so weight / pack is not relevant 比的是下降的比例,自己和自己比的下降比例,所以与自重无关
文中说glass减少的重量对于aluminum,如果说glass本身比aluminum重,则并不能说明glass重量百分比下降的比铝多
文章跑出的疑问是percentage,和重量本身无关。 aluminum cans 被recycle的数量很多,为什么下降的比例没有那么多?这是一个比例和绝对数量的问题,那就是aluminum cans在市场中的基数比glass bottles多。
玻璃瓶重量下降的百分比比铝瓶重量下降的百分比大 A 百分比和重量不能比较 B 只要瓶子回收了就行了,与瓶子里面装的东西与关 C 把玻璃瓶换成了塑料瓶,回收的玻璃瓶数量就大量减少,那玻璃瓶重量下降的百分比就比铝瓶重量下降的百分比大 D 绝对数和百分比不能比较 E 无关选项
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