souvik101990
From 2000 to 2010, beverage containers accounted for a steadily decreasing percentage of the total weight of domestic garbage in the Brazil. The increasingly widespread practice of recycling aluminum and plastic was responsible for most of this decline. However, although aluminum recycling was more widely practiced in this period than plastic recycling, it was found that the weight of plastic bottles in domestic garbage declined by a greater percentage than the weight of aluminum cans.
Which of the following, if true of the Brazil in the period 2000 to 2010, most helps to account for the finding?
A. Plastic bottles are significantly heavier than aluminum cans of comparable size.
B. Recycled aluminum cans were almost all beverage containers, but a significant fraction of the recycled plastic bottles had contained products other than beverages.
C. Manufacturers replaced many plastic bottles, but few aluminum cans, with polymer containers.
D. The total weight of plastic bottles purchased by domestics increased at a slightly faster rate than the total weight of aluminum cans.
E. In many areas, plastic bottles had to be sorted by color of the plastic before being recycled, whereas aluminum cans required no sorting.
Day 1 Question of the Verbal Contest:
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Observation:
Although aluminum recycling was more widely practiced in this period than plastic recycling, (Say people recycled 50% of aluminum cans they got and only 30% of plastic bottles they got)
but it was found that the weight of plastic bottles in domestic garbage declined by a greater percentage than the weight of aluminum cans.
We are told that plastic weight is declining more (say from 200 tonnes to 100 tonnes i.e. 50% reduction in weight) than aluminum weight (say from 100 tonnes to 70 tonnes i.e. 30% reduction in weight)
What can explain this?
A. Plastic bottles are significantly heavier than aluminum cans of comparable size. Irrelevant. Note that we are comparing the reduction in terms of percentage. The percentage reduction in weigh of plastic waste is 50%.
The weight of plastic bottles decides whether the total weight of trash was 200 tonnes or 100 tonnes etc. depending on whether plastic bottles are heavy or light. After reduction of 50%, it would become 100 tonnes or 50 tonnes. But the 50% will not change.
The reduction of weight of aluminum is also relative to its own previous weight. If previously aluminum waste was 100 tonnes, it reduced and became 70 tonnes.
But if more aluminum recycling is taking place then aluminum should see a higher percentage reduction. It doesn't explain why it doesn't happen.
B. Recycled aluminum cans were almost all beverage containers, but a significant fraction of the recycled plastic bottles had contained products other than beverages.What portion of aluminum was beverage containers and what portion of plastic bottles were beverage containers is irrelevant. What we have to explain has nothing to do with beverage containers in any case. The paradox is related to percentages of aluminum and plastic recycled (beverage containers or other uses) vs percentage of reduction in weight of aluminum vs plastic.
Beverage containers are mentioned to introduce the topic only, nothing else.
C. Manufacturers replaced many plastic bottles, but few aluminum cans, with polymer containers.Correct. We see that plastic bottles weight is reducing and the reason for that is that less plastic is being used. Say 200 tonnes of plastic was used in and discarded in 2000.
Now only 100 tonnes is discarded. Why 100 tonnes less?
Some of it is because of recycling say 60 tonnes reduction and some of it is because less plastic is being used in 2010 say 40 tonnes reduction.
That is why there is higher reduction in plastic.
Answer (C)