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Some of the students enrolled at college T are parttime [#permalink]
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Updated on: 21 Oct 2014, 23:11
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Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000? 1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000.
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Re: Some of the students enrolled at college T are parttime [#permalink]
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26 Apr 2008, 19:02
jimmyjamesdonkey wrote: Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000?
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000. Bthis is Ctrap 2. Number of students enrolled at T in 1999 = (p+f) [p=parttime students and f=fulltime students] So, fulltime students in 1999 = fNumber of students enrolled at T in 2000 = 1.05(p+f), so fulltime students in 2000 = 1.05*f%increase of fulltime student = [1.05*f f]/f = 5%
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Re: Some of the students enrolled at college T are parttime [#permalink]
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26 Apr 2008, 20:44
jimmyjamesdonkey wrote: incorrect. sondenso wrote: Number of students enrolled at T in 2000 = 1.05(p+f), so fulltime students in 2000 = 1.05*f I think this is error reasoning! Let wait for another response. I am a little confused
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Re: Some of the students enrolled at college T are parttime [#permalink]
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26 Apr 2008, 22:51
There is no information about increase/decrease of part time students in either statement so my pick is E , let me know what is OA.
if you pick numbers lets say in 99
FullTime=700 partTime=300
in 2000
FullTime=750 partTime=300 (stays the same since 5% increase is all counted in Full Time students )
scenario 2
in 99 FullTime =1300 PartTime=700 in 2000 FullTime=1350 Partime=750
% increase of fulltime students gives different answer for both the scenarios and hence my answer is E



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Some of the students enrolled at college T are parttime [#permalink]
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Updated on: 11 Sep 2011, 00:43
Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000? 1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000. Image: Attachment:
GPrep_Full_time_students.jpg [ 70.77 KiB  Viewed 6658 times ]
Originally posted by DeeptiM on 10 Sep 2011, 05:15.
Last edited by fluke on 11 Sep 2011, 00:43, edited 1 time in total.
OA corrected.



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Re: Gprep  Fulltime students!! [#permalink]
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11 Sep 2011, 01:30
vinayaerostar wrote: Answer E Answer should be E, and if you want to find the% increase of some thing then in that case we need to have to 2 data available. 1. Change( which is thr in 1 part) 2. original value or the value of fall 1999 so only one information is available so answer is E. hope it helps



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Re: Gprep  Fulltime students!! [#permalink]
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11 Sep 2011, 03:04
DeeptiM wrote: Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000?
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000.
CASE 1:
 Total Students  Fulltime students  Parttime Students  Fall 1999  100  10  90  Fall 2000  105  60  45  % Change  5% increase  50 more students, a 500% increase  Not Required 
CASE 2:
 Total Students  Fulltime students  Parttime Students  Fall 1999  100  25  75  Fall 2000  105  75  30  % Change  5% increase  50 more students, a 200% increase  Not Required 
Not Sufficient. Ans: "E"
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Re: Some of the students enrolled at college T are parttime [#permalink]
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21 Oct 2014, 19:09
jimmyjamesdonkey wrote: Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000?
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000. (1) insufficient (2) no differentiation between parttime and fulltime students insufficient (together) we still don't know anything about the # of parttime students, which is an essential contributor to the 5% increase mentioned in statement (2) examples:  if there are 0 parttime students in both years, then the # of fulltime students has increased by 5%  if the # of fulltime students has increased from 0 to 50 but the # of parttime students has remained constant at 1000 (so that 50 is 5 percent of the enrollment), then the # of fulltime students has grown by infinity% ...and anything in between answer = E



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Re: Some of the students enrolled at college T are parttime [#permalink]
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30 Sep 2016, 23:27
VeritasPrepKarishma, Bunuel, chetan2uI did understood the solution and agree that answer should be E, but I also fall into trap of choosing B in the first go. Could you please explain how to answer this question algebraically without taking numbers? I am just not able to understand whats wrong with the approach of taking initial values to be X+Y and final values 1.05(X+Y)!



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Re: Some of the students enrolled at college T are parttime [#permalink]
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08 Oct 2016, 02:53
Hello Moderators, any update on this one?



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Re: Some of the students enrolled at college T are parttime [#permalink]
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06 Feb 2017, 11:39
(1) no indication of the size of the student body insufficient (2) no differentiation between parttime and fulltime students insufficient (together) we still don't know anything about the # of parttime students, which is an essential contributor to the 5% increase mentioned in statement (2) examples:  if there are 0 parttime students in both years, then the # of fulltime students has increased by 5%  if the # of fulltime students has increased from 0 to 50 but the # of parttime students has remained constant at 1000 (so that 50 is 5 percent of the enrollment), then the # of fulltime students has grown by infinity% ...and anything in between answer = e
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Re: Some of the students enrolled at college T are parttime [#permalink]
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06 Sep 2017, 22:46
Sn: the new number of full time students. So : the old number of full time students
The question is asking for Z as Z = ( Sn  So) / So
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999.
=> Sn  So = 50 We dont know So value so we cannot calculate Z. Insuff.
2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000.
=> We have no clue whether an increase in the number of total student corellates with a rise in the number of full time students or not. Insuff. So E is the answer.
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Some of the students enrolled at college T are parttime [#permalink]
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23 May 2018, 19:05
Quote: Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000?
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000.
bumping gmatbusters niks18 amanvermagmat Bunuel VeritasPrepKarishma for validating the approach/ suggesting an efficient one. Step 1: simplify the questions stem to simplest form, I used algebraic approach to form linear equations. Step 2: write algebraic form of equations for both the statements. As seen here, the main question asks for ratio of difference of absolute values in numerator to the absolute value in denominator. St 1 gives the difference, but the absolute value of denominator is not known. St 2 seems to be providing no info in the context of what the question is asking. Combining the statements, I still do not see arriving at an unique value for denominator, Hence (E) Edit: Reply edited.
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Some of the students enrolled at college T are parttime [#permalink]
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26 May 2018, 21:30
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. Since we do not know the number of full time students, this 50 can be very small or very large. if in 1999, there was only 1 full time student, and in 2000 number increased by 50, then no. of students = 51 % increase = \(\frac{50}{1}\)*100 = 5000% if in 1999, there were 1000 full time student, and in 2000 number increased by 50, then no. of students = 1050 % increase = \(\frac{50}{1000}\)*100 = 5% Hence insufficient. (PS: you need not do the above calculation. Remember since we do not know the base value, increase in value will never be sufficient to find the percentage increase.)2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000. It is similar to St 1: since we don't know the initial total number of students, we can not find the number of total number/full time students. hence insufficient. Even after combining St 1 & 2, we are unable to find the number of full time students which is required to find the % increase in full time students. Hence NOT SUFFICIENT. Check your understanding :if we change the second statement as: New Statement2):The number of full time students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000. Now find the number of Part time time students in 2000.adkikani wrote: Quote: Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000?
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000.
bumping gmatbusters niks18 amanvermagmat Bunuel VeritasPrepKarishma for validating the approach/ suggesting an efficient one.
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Re: Some of the students enrolled at college T are parttime [#permalink]
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26 May 2018, 21:52
Hi adkikaniYour equation for second statement is flawed, you forgot to put a bracket required to provide the effect of factor of 1.05. See sketch. Attachment:
Q1.jpeg [ 69.05 KiB  Viewed 386 times ]
now , even if you get correct equations, if you are not able to conclude further, it is not of much use. In my opinion, this is not the best approach. adkikani wrote: Quote: Some of the students enrolled at college T are parttime students and the rest are fulltime. By what percent did the number of fulltime students enrolled at college T increase from fall of 1999 to the fall of 2000?
1) There were 50 more fulltime students enrolled at college T in the fall of 2000 than in the fall of 1999. 2) The total number of students enrolled at college T increased by 5 percent from the fall of 1999 to the fall of 2000.
bumping gmatbusters niks18 amanvermagmat Bunuel VeritasPrepKarishma for validating the approach/ suggesting an efficient one.
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Some of the students enrolled at college T are parttime [#permalink]
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26 May 2018, 23:03
Nice catch gmatbusters Quote: now , even if you get correct equations, if you are not able to conclude further, it is not of much use. I have edited the steps in my original post to clear the fog.
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