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Manhattan CAT extinction

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Manhattan CAT extinction

by Neo Anderson » Sat May 12, 2012 6:51 am
Ten years ago, scientists predicted that the animal z would become extinct in t years. What is t?

(1) Animal z became extinct 4 years ago.

(2) If the scientists had extended their extinction prediction for animal z by 3 years, their prediction would have been incorrect by 2 years.

[spoiler]OA after some time![/spoiler]
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by krishna239455 » Sat May 12, 2012 7:34 am
IMO: A

Statement 1: 10 yrs ago from now it was predicted and it extincted 4 yrs ago from now. It means 10-4 = 6 yrs
t=6 yrs SUFFECIENT

Statement 2: There is nothing given on specific time of prediction INSUFFECIENT
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by neelgandham » Sat May 12, 2012 7:54 am
Ten years ago, scientists predicted that the animal z would become extinct in t years. What is t?
(1) Animal z became extinct 4 years ago.
Statement 1 is sufficient to answer the question IF ( and a BIG IF) the scientists prediction has come true. Then t = 10-4 = 6 years

Statement 1 is Insufficient to answer the question IF ( and a BIG IF) the scientists prediction has gone wrong.
(2) If the scientists had extended their extinction prediction for animal z by 3 years, their prediction would have been incorrect by 2 years.
Since, there is no relation between the prediction and the actual time of extinction, Statement 2 is Insufficient to answer the question.
Statement 1 + 2
(Let us assume that the prediction has gone wrong)
If the scientists have extended the prediction by 3 years(t+3 years), the prediction would be incorrect by 2 years i.e the actual extinction is after t+1((t+3)-2) or t+5((t+3)+2) years from the time of scientist's prediction.
So, t+1 = 6 or t+5 = 6 (From Statement 1)
t = 5 or t = 1
So, we don't have a single answer to the question.

Correct answer choice = A IF ( and a BIG IF) the scientists prediction has come true.
Correct answer choice = E IF ( and a BIG IF) the scientists prediction has gone wrong.

I am not sure if this question qualifies as a GMAT MATH question![/quote]
Anil Gandham
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by krishna239455 » Sat May 12, 2012 8:15 am
I agree with you, neelgandham

To remove the confusion the statement 1 should be written as "Animal z became extinct 4 years ago, this is wat was also predicted by scientists"
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by Anaira Mitch » Sun Jan 15, 2017 8:35 pm
The question does not ask for the actual number of years ago that animal z became extinct. Instead it asks for t, the number of years scientists predicted it would take for animal z to become extinct.

(1) INSUFFICIENT: This tells us that animal z became extinct 4 years ago but it does not provide information about t.

(2) INSUFFICIENT: This provides a relationship between the predicted time of extinction time and the actual time of extinction but does not provide any actual values for either.

(1) AND (2) INSUFFICIENT: The easiest way to approach this problem is to imagine a time line from 0 to 10. The scientists made their prediction 10 years ago, or at 0 years.

From statement (1) we know that animal z became extinct 4 years ago, or at 6 years.

From statement (2) we know that if the scientists had extended their prediction by 3 years they would have been incorrect by 2 years. The key to this question is to realize that "incorrect by 2 years" could mean 2 years in either direction: 6 + 2 = 8 years or 6 - 2 = 4 years.

From here, we can write two simple equations:

t + 3 = 8 OR t + 3 = 4
t = 5 t = 1

This gives us two different values for t, which means that (1) and (2) together are not sufficient to come up with one definitive value for t. The correct answer is E.
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by Matt@VeritasPrep » Wed Jan 18, 2017 6:12 pm
krishna239455 wrote:I agree with you, neelgandham

To remove the confusion the statement 1 should be written as "Animal z became extinct 4 years ago, this is wat was also predicted by scientists"
It's important to point out that the confusion here is DELIBERATE: the author of the question is testing whether you notice this distinction without it being made explicit.
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