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Ten years ago, scientists predicted that the animal z would

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chitrangada.maitra
 Post subject: Ten years ago, scientists predicted that the animal z would
 Post Posted: Tue Sep 28, 2010 6:06 pm 
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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.

OA: E

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

My question is: From statement 1, doesnt 10-4=6 give us the value of t? (Scientists predicted 10 years ago. The animal was extinct 4 years ago. So T=6)
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gokul_nair1984
 Post subject: Re: Ten years ago, scientists predicted that the animal z would
 Post Posted: Wed Sep 29, 2010 3:15 am 
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chitrangada.maitra wrote:
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.


chitrangada.maitra wrote:
My question is: From statement 1, doesnt 10-4=6 give us the value of t? (Scientists predicted 10 years ago. The animal was extinct 4 years ago. So T=6)


Let's assume right now it is Year 'x'
So 10 years ago, it should have been Year 'x-10' and at that time it was predicted that 'z' would take 't' years to be extinct.
Thus 'z' would be extinct in the year 'x-10+4'='x-6'. From this we know that 't' has to be 6 years. However. the scientist's prediction need not be true.I thought of this only after reading the Statement 2 that the prediction could be incorrect.
This is a new genre of Questions from MGMAT, DS fused in with CR. . For this to be true, there is an assumption that the prediction need not be true. :)

Bad Question, I would say. What if the prediction were to come true, Then your answer (6) is right. This 'Prediction to be untrue' cannot be an assumption(unstated), it should be presented as a fact else statement 1 is sufficient per se. Things, should be much clearer on the real stuff!
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poonamchiK
 Post subject: Re: Ten years ago, scientists predicted that the animal z would
 Post Posted: Wed Sep 29, 2010 4:17 am 
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Hi there,
10 yrs ago from when. So u need to understand that there is no absolute value only relative values in the question. hence i would go with e.

P
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gokul_nair1984
 Post subject: Re: Ten years ago, scientists predicted that the animal z would
 Post Posted: Wed Sep 29, 2010 6:02 am 
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Posts: 170
@ poonamchiK

The question asks for the value of t, which has to be absolute, if you need a concrete value.If it is relative, the value will surely be E. Here, my point is how would you know that the scientist's prediction could be untrue? You get an idea about that only when you look at Statement 2.

poonamchiK wrote:
10 yrs ago from when. So u need to understand that there is no absolute value only relative values in the question


It's 2010 now: Hence, 10 years ago, it was 2000.
If the scientists say that 'z' became extinct 4 years ago, this means, t=(2010-4)-2000= 6years. This value will never change and is not relative in any way.Whatever year you consider and apply this logic , you'll always get 6 years.

But the real trick here is that the Prediction need not hold good!Let's assume you are only given statement 1 and statement 2 was let's say: Animal 'z' is heavier than an elephant(something totally irrelevant). What would your answer in this case be? (A) for sure right, because you would never think of (the prediction to not hold good) case.That's because the statements are basically facts that are analogous to premises in CR, ie;they must be true. But, here in the form of the second sentence , we know that there could plausibly be a case(an assumption) where the prediction might not come true.

The answer is (E) though..
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tim
 Post subject: Re: Ten years ago, scientists predicted that the animal z would
 Post Posted: Fri Oct 08, 2010 1:13 am 
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Thanks, Gokul. let us know if you have any further questions..

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Tim Sanders
Manhattan GMAT Instructor
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remenyi86
 Post subject: Re: Ten years ago, scientists predicted that the animal z would
 Post Posted: Sun Dec 11, 2011 8:16 pm 
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I haven't seen anything in the MGMAT strategy guides that mention anything like this problem. Would a problem like this actually appear on the GMAT?
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tim
 Post subject: Re: Ten years ago, scientists predicted that the animal z would
 Post Posted: Tue Dec 13, 2011 2:50 am 
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Not likely. This looks too much like a hybrid between DS and CR that i wouldn’t expect a question like this to show up on the test..

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Tim Sanders
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