A plastics factory next to Hullson River dumps its waste, which contai

Question

A plastics factory next to Hullson River dumps its waste, which contains a certain toxin,​directly into the river. The amount of waste the factory dumps into the river is directly proportional to the amount of plastic the factory produces. This year, the factory produced 50% more plastic than last year. Yet measurements taken 50 yards downstream of the waste dump site show that concentrations of the toxin were significantly lower than they were at the same site last year.

Which of the following, if true, does the most to explain the surprising finding?

(A) The factory is considering adopting a production technique that would drastically reduce the amount of the toxin produced.

(B) Unseasonably heavy rains have increased the volume of water in Hullson River by 75%.

(C) In studies, high concentrations of the toxin in water have been shown to inhibit certain species of fish from laying eggs.

(D) When the plastic factory produces more plastic, the concentration of the toxin within the waste dumped into the river increases.

(E) Another factory, located upstream from the plastics factory, produces waste containing a different toxin and dumps that waste into the river.

gloomybison · Accepted Answer

(A) The factory is considering adopting a production technique that would drastically reduce the amount of the toxin produced.
The factory is till considering means that they re yet to adopt. So it can't have any effect on the water analysis results that are already in and show that toxins levels are much lower

(B) Unseasonably heavy rains have increased the volume of water in Hullson River by 75%.
 Correct 
if the water level increased more than did the plastic level, it is normal to see a decrease in toxin percentage in water
İmagine that in previous years you have 100 tonnes of water and 50 tonnes of toxic whereas this year you have 175 tonnes of water and 75 tonnes of plastic. In the previous scenario you have %50 of toxins but in the second scenario you have 42% of toxins

(C) In studies, high concentrations of the toxin in water have been shown to inhibit certain species of fish from laying eggs.
Irrelevant, neither do we care about fishes nor about their eggs

(D) When the plastic factory produces more plastic, the concentration of the toxin within the waste dumped into the river increases.
It just repeats what we already know in the question stem

(E) Another factory, located upstream from the plastics factory, produces waste containing a different toxin and dumps that waste into the river.
Out of scope, if anything we would expect an increase in the toxin levels

kungfury42 · Answer

I think what's happening in the passage above is abundantly clear. This year the factory produced 50% more plastics and we had expected to find a significantly higher concentration of toxin at our sample site, however it turned out to be even lower than last year. What's happening? I think any of these three situations could be a possibility:

1. The factory uses a method of production such that the amount of toxin generated is inversely proportional to the amount of plastics produced

2. The factory has adopted a new method of producing plastics that generate lesser amount of toxin per unit of plastics produced

3. Since we are interested in the concentration (%age weight by volume) and not in the absolute quantity of the toxin, could it be such that the denominator (volume of water in the river) increased?
 
 Extremely tempting choice as it matches with the possibility (1) discussed above. However, note that there is a subtle catch here.  The factory is still considering this decision and hasn't finalized it yet.  Which means this cannot be a possible reason for the surprising findings this year.  Eliminate A. 
 
  Matches with the 3rd possibility we had discussed above and seems like a perfectly reasonable choice.  The amount of toxin generated may have been higher, however since the volume of water in the river increased, the toxin got a greater volume of water to distribute itself, and thus the amount of toxin found per unit volume of the river water became lesser than last year.  To verify our hypothesis we know that the amount of toxin could've increased by a maximum of 50% and that the volume of river water increased by 75%, a greater quantity in the denominator than in the numerator, resulting in an overall decrease in the value of the fraction. B seems like a perfect answer. 
 
 Unless the fishes ganged up and did something to the toxin (to reverse its effect on them laying eggs) I don't see this to be a reason to find a lower concentration of toxin in the river water this year.  And in all seriousness, if this is a valid possibility, I believe we should breed more of such fishes to fight off the river wastes and harmful toxins they contain. But looks like a stretch for now. Eliminate C. 
 
 I think this point was fairly implied when we were reading the passage. And for it to be explicitly mentioned makes no sense,  if anything, the opposite of it  (the concentration of the toxin within the waste dumped into the river deceases as the plastic factory produces more plastic)  should've been mentioned, if that were a possibility, and that would've admittedly made for a very challenging option choice for option B. Anyway, as it is right now, we have no choice but to eliminate D. 
 
  Does this another factory produce a kind of toxin that's an antidote to the toxin in discussion?  If only this were true we could've had a possibility of option E justifying why we found lesser concentrations of the original toxin even after it was presumably generated in greater quantity this year.  But as it stands right now, option E cannot be a valid answer. Eliminate E.

We have eliminated options A, C, D, and E, and are only left with option B as a valid choice. Hence, answer should be option B.

Posted from my mobile device

desertEagle · Answer

Argument
toxin production is directly proportional to amount of plastic produced
Plastic produced increase, but toxin concentration decreased.

Question type
Explain the discrepancy. This can happen only if someone takes out toxins by water treatment or some new fish eats and thrives on toxins eats all the toxins or if water concentration is increased somehow.

(A) The factory is considering adopting a production technique that would drastically reduce the amount of the toxin produced. --> C onsidering does not mean implemented. If it were implemented, then we could conclude that this was case. --> Does not explain --> INCORRECT

(B) Unseasonably heavy rains have increased the volume of water in Hullson River by 75%. -->  yes. If water increases more than toxin level, concentration will decrease. Here toxin levels increase by 50% but water volume increases by 75%. So the ratio(concentration) will decrease --->CORRECT

(C) In studies, high concentrations of the toxin in water have been shown to inhibit certain species of fish from laying eggs. -->  Laying of eggs is not the issue, decrease in concentration is --> OUT OF SCOPE --> INCORRECT

(D) When the plastic factory produces more plastic, the concentration of the toxin within the waste dumped into the river increases. -->  This just states whats given in argument --> Does not help explain the discrepancy. --> INCORRECT

(E) Another factory, located upstream from the plastics factory, produces waste containing a different toxin and dumps that waste into the river. --> t hat means more toxin. Concentration must increase. --> Reverse Logic --> INCORRECT

Ans B

TarunKumar1234 · Answer

A plastics factory next to Hullson River dumps its waste, which contains a certain toxin,directly into the river. The amount of waste the factory dumps into the river is directly proportional to the amount of plastic the factory produces. This year, the factory produced 50% more plastic than last year. Yet measurements taken 50 yards downstream of the waste dump site show that concentrations of the toxin were significantly lower than they were at the same site last year.

Resolve the Paradox: The more production of plastics the more waste dump into the river. Produced increased by 50%, but toxin few yards away reduced.

Which of the following, if true, does the most to explain the surprising finding?

(A) The factory is considering adopting a production technique that would drastically reduce the amount of the toxin produced. -> But, 50% increase in production may cause the toxin into river higher(less than 50% increase) or same or lower level. Incorrect.

(B) Unseasonably heavy rains have increased the volume of water in Hullson River by 75%. -> 50% production increased but heavy rains increased 75% then toxin into the river decreased definitely. Let's keep it.

(C) In studies, high concentrations of the toxin in water have been shown to inhibit certain species of fish from laying eggs. -> it doesn't resolve why the toxin into the river is less. Incorrect.

(D) When the plastic factory produces more plastic, the concentration of the toxin within the waste dumped into the river increases. -> Strengthen the argument, doesn't resolve the paradox. Incorrect.

(E) Another factory, located upstream from the plastics factory, produces waste containing a different toxin and dumps that waste into the river. -> then, toxin into the river can increase also. Incorrect.

So, I think B.

VerbalBot · Answer

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A plastics factory next to Hullson River dumps its waste, which contai

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