Hi: Can someone please help me with this very simple question?
Q: Company P had 15% more employees in Dec than it had in Jan. If company P had 460 employees in Dec, how many employees did it have in Jan?
My approach was to assume Dec employee number as 100% and Jan employee number as 85%. But the answer solved this question assuming Dec as 115% and Jan as 100%.
Can anybody tell me why???
Thanks! =)
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Percent (OG13, p.159, Q57 )
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Brent@GMATPrepNow
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Let J = # of employees in Janschao wrote: Q: Company P had 15% more employees in Dec than it had in Jan. If company P had 460 employees in Dec, how many employees did it have in Jan?
So, 1.15J = # of employees in Dec
This means that 1.15J = 460
So, J = 460/1.15 = 400
Cheers,
Brent
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This is a common error.schao wrote: My approach was to assume Dec employee number as 100% and Jan employee number as 85%. But the answer solved this question assuming Dec as 115% and Jan as 100%.
Can anybody tell me why???
Thanks! =)
You are taking the information that A is 15% greater than B and concluding that B must be 15% less than A.
To see the problem, let's use different (easier) numbers.
Say that A = 100 and B = 150
So, we can say that B is 50% greater than A.
But can we also say that A is 50% less than B? No. A is 33 1/3% less than B.
Cheers,
Brent
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GMATGuruNY
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ALWAYS LOOK AT THE ANSWER CHOICES.Company P had 15 percent more employees in December than it had in January. If Company P had 460 employees in December, how many employees did it have in January?
391
400
410
423
445
The answer choices here represent the number of employees in January.
There were 15% MORE employees in December.
Thus, 15% of the correct answer choice must yield an integer value.
Only answer choice B is viable.
The correct answer is B.
Last edited by GMATGuruNY on Fri Jan 11, 2013 8:20 am, edited 1 time in total.
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As a tutor, I don't simply teach you how I would approach problems.
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Brent@GMATPrepNow wrote:Let J = # of employees in Janschao wrote: Q: Company P had 15% more employees in Dec than it had in Jan. If company P had 460 employees in Dec, how many employees did it have in Jan?
So, 1.15J = # of employees in Dec
This means that 1.15J = 460
So, J = 460/1.15 = 400
Cheers,
Brent
Hello Brent =)Thanks for your reply.
I can understand the workings.
But the part that i get confused is that why do you solve this question using 1.15J = 460, not 0.85D = J?
I get it after seeing your second reply! Thank you very much!
