Forum Home > GMAT > Quantitative > Problem Solving (PS)
Events & Promotions
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Oct 1306:00 AM PDT
-06:30 AM PDT
Solve GRE practice problems covering Quant (One answer choice and multiple answer choice), Data Interpretation, Text Completion, Sentence Equivalence, and Reading Comprehension Problems.- Oct 13
06:30 AM PDT
-07:30 AM PDT
Today we are covering a phenomenal GMAT story of Vatsal who scored 715 - which is 99.5 percentile score - on his latest GMAT focus test, USING NOTHING BUT GMAT CLUB forum quiz, GMAT Club’s YouTube videos and official questions. - Oct 13
07:30 AM PDT
-08:15 AM PDT
olve 30 GMAT Focus practice problems covering Problem Solving, Data Sufficiency, Data Insights, Reading Comprehension, and Critical Reasoning. Take this GMAT practice quiz live with peers, analyze your GMAT study progress, and see where you stand. 
Oct 1311:00 AM IST
-01:00 PM IST
Attend this session to evaluate your current skill level, learn process skills, and solve through tough Arithmetic questions
Oct 0810:00 AM EDT
-11:59 PM EDT
For a limited time use code TAKE15 to save on prep. Valid on Complete Course, Advanced Course, Bootcamp Course, Tutoring, and the Executive Assessment Course. This discount ends October 28, 2024.- Oct 15
08:30 AM PDT
-08:30 AM PDT
You'll learn how our seasoned experts have successfully helped countless applicants achieve their dream schools. With a clear understanding of the application process, including deadlines and more. - Oct 16
08:30 AM PDT
-12:00 PM PDT
Are you ready to take the next step in your academic and professional journey? If you’re aspiring to join one of the top 15 MBA programs, we’ve got an exciting opportunity just for you! Welcome to the GMAT Club's Free Interview Prep Event - Oct 18
08:00 AM PDT
-09:00 AM PDT
Are you gearing up for your ISB MBA interview? In this video, we dive deep into the common questions you may encounter and provide essential preparation tips to help you stand out from the crowd. 
Oct 1810:00 AM EDT
-12:00 PM EDT
Have you ever wondered how to score a PERFECT 805 on the GMAT? Meet Julia, a banking professional who used the Target Test Prep course to achieve this incredible feat. Julia's story is nothing short of an inspiration.- Oct 19
11:00 AM IST
-01:00 PM IST
Attend this session to learn how to Deconstruct arguments, Pre-Think Author’s Assumptions, and apply Negation Test. 
Oct 1901:00 PM EDT
-02:00 PM EDT
Think a 100% GMAT Verbal score is out of your reach? Target Test Prep will make you think again! Our course uses techniques such as topical study and spaced repetition to maximize knowledge retention and make studying simple and fun.
A plastics factory next to Hullson River dumps its waste, which contai
[#permalink]
07 Feb 2022, 02:30
07 Feb 2022, 02:30
3
Bookmarks
Expert Reply
Show timer
00:00
A
B
C
D
E
Difficulty:
15%
(low)
Question Stats:
81% (01:28) correct
19%
(01:45)
wrong
based on 236
sessions
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.
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.
Joined: 30 Mar 2021
Posts: 227
Given Kudos: 93
Location: Turkey
Schools: Yale '26 (A) LBS '26 (WL) Booth '26 (A) Columbia CBS'26 (A) Kellogg '26 (A) Tuck '26 (A) Wharton '26 (D) Sloan '26 (D)
GMAT 1: 720 Q51 V36 
GPA: 3.69
Re: A plastics factory next to Hullson River dumps its waste, which contai
[#permalink]
07 Feb 2022, 04:56
07 Feb 2022, 04:56
5
Kudos
(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
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
General Discussion
A plastics factory next to Hullson River dumps its waste, which contai
[#permalink]
07 Feb 2022, 04:53
07 Feb 2022, 04:53
4
Kudos
Bunuel
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.
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: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.
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?
Quote:
(A) The factory is considering adopting a production technique that would drastically reduce the amount of the toxin produced.
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.Quote:
(B) Unseasonably heavy rains have increased the volume of water in Hullson River by 75%.
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.Quote:
(C) In studies, high concentrations of the toxin in water have been shown to inhibit certain species of fish from laying eggs.
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.Quote:
(D) When the plastic factory produces more plastic, the concentration of the toxin within the waste dumped into the river increases.
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.Quote:
(E) Another factory, located upstream from the plastics factory, produces waste containing a different toxin and dumps that waste into the river.
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
