Hello,
Can you please assist with this question? This is from MGMAT. Thanks for your help.
A certain research group plans to create computer models of x% of a list of 10,000 bacterial species known to inhabit the human body. After a budget cut, the group finds it must reduce this selection by (x − 5)%. In terms of x, how many species of bacteria will the group be able to model?
OA: [spoiler](x)(105 - x)[/spoiler]
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A certain research group plans to create computer models...
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gmattesttaker2
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ganeshrkamath
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Number of specied that the group plans to model = x% of 10000 = x/100 * 10000 = 100xgmattesttaker2 wrote:Hello,
Can you please assist with this question? This is from MGMAT. Thanks for your help.
A certain research group plans to create computer models of x% of a list of 10,000 bacterial species known to inhabit the human body. After a budget cut, the group finds it must reduce this selection by (x − 5)%. In terms of x, how many species of bacteria will the group be able to model?
OA: [spoiler](x)(105 - x)[/spoiler]
Reduce by (x-5)% :
Number of species that the group will be able to model = 100x * (100 - (x-5))/100
= [spoiler]x * (105 - x)
[/spoiler]
Take an example : x = 30
30% of 10000 = 3000
Reduce by 25% => 3000 * (100-25)/100
= 3000 * 75/100 = 2250
30*(105-30) = 30*75 = 2250
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ganeshrkamath
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Please explain how you arrived at your answer.Java_85 wrote:I think the answer is 100x-500 , and don't think the OA is right. Please correct me if I'm wrong.
I'm getting the same answer as the OA (see above).
Cheers
Every job is a self-portrait of the person who did it. Autograph your work with excellence.
Kelley School of Business (Class of 2016)
GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494
Kelley School of Business (Class of 2016)
GMAT Score: 750 V40 Q51 AWA 5 IR 8
https://www.beatthegmat.com/first-attemp ... tml#688494
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GMATGuruNY
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Since the answer choices on the GMAT would all be IN TERMS OF A VARIABLE -- x -- we could PLUG IN.gmattesttaker2 wrote: A certain research group plans to create computer models of x% of a list of 10,000 bacterial species known to inhabit the human body. After a budget cut, the group finds it must reduce this selection by (x − 5)%. In terms of x, how many species of bacteria will the group be able to model?
Let x = 25.
Number of models before the budget cut = x% of 10,000 = 25% of 10,000 = 2500.
Percentage decrease after the budget cut = x-5 = 25-5 = 20%
Number of models after the 20% decrease = 2500 - .2(2500) = 2500-500 = 2000. This is our target.
Now we plug x=25 into the answers to see which yields our target of 2000.
Answer choice: (x)(105 - x) = 25(105-25) = 25(80) = 2000.
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Java_85
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I was saying that (x/100)* 10000= 100x initial number of modelsganeshrkamath wrote:Please explain how you arrived at your answer.Java_85 wrote:I think the answer is 100x-500 , and don't think the OA is right. Please correct me if I'm wrong.
I'm getting the same answer as the OA (see above).
Cheers
we're decreasing it to (x-5/100)*10000=> 100x-500 is the number of species we can model.
Which is also correct, but different
Last edited by Java_85 on Mon Aug 19, 2013 4:13 pm, edited 1 time in total.
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gmattesttaker2
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Hello Mitch,GMATGuruNY wrote:Since the answer choices on the GMAT would all be IN TERMS OF A VARIABLE -- x -- we could PLUG IN.gmattesttaker2 wrote: A certain research group plans to create computer models of x% of a list of 10,000 bacterial species known to inhabit the human body. After a budget cut, the group finds it must reduce this selection by (x − 5)%. In terms of x, how many species of bacteria will the group be able to model?
Let x = 25.
Number of models before the budget cut = x% of 10,000 = 25% of 10,000 = 2500.
Percentage decrease after the budget cut = x-5 = 25-5 = 20%
Number of models after the 20% decrease = 2500 - .2(2500) = 2500-500 = 2000. This is our target.
Now we plug x=25 into the answers to see which yields our target of 2000.
Answer choice: (x)(105 - x) = 25(105-25) = 25(80) = 2000.
Thank you very much for the excellent explanation.
Best Regards,
Sri
