Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

 It is currently 17 Jul 2019, 07:42

### 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

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati

Author Message
TAGS:

### Hide Tags

Manager
Joined: 12 Mar 2017
Posts: 224
Location: India
Concentration: Strategy, General Management
GMAT 1: 630 Q49 V27
GPA: 4
Re: GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati  [#permalink]

### Show Tags

01 Mar 2018, 08:12
8mins and 30 seconds. All correct
Intern
Joined: 24 Jan 2018
Posts: 10
Re: GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati  [#permalink]

### Show Tags

29 Mar 2018, 23:26
Why is it assumed that microorganisms always contaminate water?

I'm fine with the reasoning that there is some other cause of algae's death, that weakens the conclusion. But microorganisms contaminating the water and hence, weakening the conclusion doesn't look convincing enough, especially when we don't know whether they contaminate water.
Manager
Joined: 17 Aug 2018
Posts: 67
GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati  [#permalink]

### Show Tags

29 Dec 2018, 21:29
Below is the explanation for question no 4.

The conclusion of the author in the 4th Paragraph is "A recent experiment has supplied a more promising
method for controlling the algae.".

Option C is implying that algae was controlled due to an alternate reason hence weakening the conclusion of the author.

I think, I deserve kudos :D
_________________
Manager
Joined: 22 Sep 2018
Posts: 249
Re: GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati  [#permalink]

### Show Tags

30 Dec 2018, 13:31
4/4 took about 9 minutes including reading the passage. Here's my reasoning if it helps anyone:

P1) solar water -> different temperatures (bottom hot + more saline, top = cooler but transparent to shoot solar energy into the bottom)

P2) potential as renewable energy source, but algae interfere. Need light to shine all the way down to bottom layer to work

P3) cannot use algae killers because of risk of easy contamination

P4) describes one method that could be successful in creating solar water

1) A is the only one that is relevant here. The entire passage talks about how algae interferes with solar water development as a renewable energy source and a potential solution for this problem.

2, 3) all discussed above in passage summary

4) The only one that would undermine the validity of the experiment would be if you added some other thing to kill the algae. For ex. if D were true, you could still run this method and the algae would die. If you were to run this experiment elsewhere and DID NOT add the micro organisms this experiment would not work again. Hence answer is C.
Manager
Joined: 01 Nov 2018
Posts: 75
GMAT 1: 690 Q48 V35
GPA: 3.88
Re: GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati  [#permalink]

### Show Tags

02 Jan 2019, 17:27
9:00min 4/4. Easy read with only one tough question (Last one). A few enticing options but only choice C introduces another factor that may have led to the demise of the algae. Wish I could speed up my timing on RC but I know my accuracy will fall quite a bit. Thankfully, I've shaved off 15 seconds on sentence correction questions
Intern
Joined: 02 Apr 2015
Posts: 39
Location: Singapore
GMAT 1: 550 Q42 V24
GMAT 2: 690 Q47 V37
GPA: 3.66
WE: Social Work (Non-Profit and Government)
Re: GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati  [#permalink]

### Show Tags

24 Jun 2019, 03:45
manishkhare wrote:
Why is B incorrect ? If The lateral motility of the algae cells that sank to the bottom of the pond was not impaired then the experiment is not successful .

Regards,
Manish Khare

Which of the following, if true, would seriously undermine the validity of the conclusions drawn from the experiment described in the last paragraph of the passage?
A. The algae cells that sank to the bottom of the pond were destroyed only after a time lag of twenty-four hours.
B. The lateral motility of the algae cells that sank to the bottom of the pond was not impaired.
C. The water with which the artificial solar pond was diluted contained microorganisms that kill algae.
D. The algae cells that sank to the bottom of the pond were actually killed by the rapid change in pressure.
E. The higher salinity brought about through evaporation increased the transparency of the upper levels of water in the pond

This method allows for effective control of nuisance algae while leaving solar ponds as one of the cleanest technologies providing energy for human use.

We have to find the ways that using this technology will actually cause more contamination.

the water in the solar pond was first made more saline through evaporation and then diluted by a rapid inflow of fresh water. This shock reduced the cells' ability to regulate the movement of water through their membranes. They rapidly absorbed water, resulting in distortions of shape, increase in volume

what if that water used for is itself contaminated. Then conclusion is no longer valid.

The lateral motility of the algae cells that sank to the bottom of the pond was not impaired.

I don't think "motility" is playing a larger role. Even if their motility is intact - this will occur - Their buoyancy adversely affected, the cells sank to the bottom of the pond, where they encountered the hot waters of the storage layer and were destroyed.

As a general test-taker, how am I supposed to the meaning of "motility", which is a biology term? I've never heard of it. I thought the word was incorrectly written for mortality.
Re: GMATPREP ChallengeQ-Solar ponds are bodies of water in which circulati   [#permalink] 24 Jun 2019, 03:45

Go to page   Previous    1   2   [ 26 posts ]

Display posts from previous: Sort by