what is this question asking

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what is this question asking

by loveusonu » Sat Jul 17, 2010 10:50 am
When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface. The brief exposure of the seeds to sunlight stimulates receptors, which have become highly sensitive to sunlight during the months the seeds were buried in the soil, and the stimulated receptors trigger germination. Without the prolonged darkness, followed by exposure to sunlight, the seeds do not germinate.

The statements above, if true, most strongly support which one of the following statements about a field that will be plowed in the spring and in which pigweed seeds have been buried in the soil all winter?

(A) Fewer pigweed plants will grow in the field if it is plowed only at night than if it is plowed during the day.
(B) Fewer pigweed plants will grow in the field if it is not plowed at all than if it is plowed only at night.
(C) Fewer pigweed plants will grow in the field if it is plowed just before sunrise than if it is plowed just after sunset.
(D) The pigweed seeds that are churned up to the surface of the soil during the plowing will not germinate unless they are redeposited under the surface of the soil.
(E) All of the pigweed seeds that are already on the surface of the soil before the field is plowed will germinate.
Sonu
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by sk818020 » Sat Jul 17, 2010 11:08 am
This is an inference question. It is asking, from the evidence given in the argument, which of the following answer choices must be true.

IMO the answer is A. If sunlight is was causes the seeds to germinate and plowing is what causes the seeds to be exposed to sunlight, then plowing at night (exposing the seeds to night), will certainly cause less seeds to germinate (and thus grow) than plowing during the day.

Can you please provide the source of the question and confirm what the official answer is?

Thanks,

Jared

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by Patrick_GMATFix » Sat Jul 17, 2010 11:14 am
This is another CR Inference (aka Draw a Conclusion) question. To solve these, select the answer that MUST BE TRUE given the premises presented.

Premise 1: the seeds are brought closer to the surface when the soil is plowed.
Premise 2: This plowing BRIEFLY exposes the receptors in the seeds to sunlight;
Premise 3: the time spent burried made recepters sensitive to light, so light exposure triggers germination.

The question basically wants you to determine which of the answers provides a valid conclusion given the premises above.

(A) The BRIEF exposure to sunlight is what triggers the germination. if plowing only occurs at night, there will be no exposure to sunlight, so plants will not germinate (and grow). This is a good conclusion.

(B) Plowing only at night is no better than not plowing at all because it is the brief exposure to sunlight during plowing that triggers germination. Neither plowing only at night, nor never plowing at all will provide the sunlight needed.

(C) Neither plowing before sunrise, nor plowing after sunset, will provide the necessary exposure to sunlight. So neither option will result in more/fewer plants.

(D) Nothing in the argument suggests that the seeds must be redeposited deep into the soil. This is not a valid conclusion.

(E) Nothing in the argument suggests that there is a 0% fail rate if germination conditions are good. We cannot conclude that ALL the seeds will germinate.

Pick A

If you have trouble with inference questions (draw a conclusion questions), set topic='CR Inference'and difficulty='600-700 & 700+' in the Drill Generator.

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by FightWithGMAT » Sat Jul 17, 2010 12:53 pm
loveusonu wrote:When soil is plowed in the spring, pigweed seeds that have been buried in the soil all winter are churned up to the surface and redeposited just under the surface. The brief exposure of the seeds to sunlight stimulates receptors, which have become highly sensitive to sunlight during the months the seeds were buried in the soil, and the stimulated receptors trigger germination. Without the prolonged darkness, followed by exposure to sunlight, the seeds do not germinate.

The statements above, if true, most strongly support which one of the following statements about a field that will be plowed in the spring and in which pigweed seeds have been buried in the soil all winter?

(A) Fewer pigweed plants will grow in the field if it is plowed only at night than if it is plowed during the day.
(B) Fewer pigweed plants will grow in the field if it is not plowed at all than if it is plowed only at night.
(C) Fewer pigweed plants will grow in the field if it is plowed just before sunrise than if it is plowed just after sunset.
(D) The pigweed seeds that are churned up to the surface of the soil during the plowing will not germinate unless they are redeposited under the surface of the soil.
(E) All of the pigweed seeds that are already on the surface of the soil before the field is plowed will germinate.
It is A

Prolonged darkness and exposure to sunlight are the necessary conditions to germinate most of the seeds (a sufficient condition)

take contrapositive of this:

Fewer seeds would germinate if either of two (prolonged darkness or exposure to sunlight) would not happen.

A is the rephrase of this contrapositive statement.

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by loveusonu » Sat Jul 17, 2010 11:22 pm
sk818020 wrote:This is an inference question. It is asking, from the evidence given in the argument, which of the following answer choices must be true.

IMO the answer is A. If sunlight is was causes the seeds to germinate and plowing is what causes the seeds to be exposed to sunlight, then plowing at night (exposing the seeds to night), will certainly cause less seeds to germinate (and thus grow) than plowing during the day.

Can you please provide the source of the question and confirm what the official answer is?

Thanks,

Jared
Thanks Jared,
This one is from CR1000 series.
I was confused between A&C, as only those are logical. However as couldn't recognize what type of question it is went wrong.
Sonu
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