What fraction of this year's graduating students at a certai

[rehab-299]

What fraction of this year's graduating students at a certain college are males?
1- of this year's graduating student, 33 % of the males and 20% of famales transferred from another college.
2- of this year's graduating students 25% transferred from another college.

[erin]

Hi - I think this question is for a GMAT instructor?

Thanks,
Erin

Erin Schuhmacher
Senior Consultant
mbaMission
www.mbamission.com

[chandran.sharat]

Source : GMAT Prep

_______|Trans|Total
--------|-----|-----
Male___|0.33M|M
Female_|0.20F|F
--------|-----|-----
_______|0.25X|X


We are asked to find M / X

0.33M + 0.20F = 0.25X (Eqn1)
M + F = X (Eqn2)

Multiplying Eqn2 by 0.20 and subtracting.

0.33M + 0.20F = 0.25X
0.20M + 0.20F = 0.20X
---------------------------
0.13M = 0.05X

M/X = 5/13

Thus C. Both statements are required.

[sudaif]

good question under timed conditions
another solution for those who didn't see this as a question that could be solved with a double matrix:

statement 1: useless
statement 2: useless

statement 1+ statement 2:
Let graduating students be = x
then number transferred = 0.25x
the sum of the number of males and females who transferred should be equal to 0.25x, thus, let number of graduating males = M and consequently, number of graduating females = X-M. We are assuming only two sexes are possible --- usually a safe assumption for GMAT quant.
next, let's sum the males and females who are transferring and equate to total number tranferring
0.33M + 0.20(X-M)=0.25X
This equation reduces to M/X=5/13
C is your answer!

[AS24]

The statements only talking about the graduating students that transferred from another college. What about the male students that are part of the "original" student population of that college. Going by that logic, I chose E.

Thanks in advance.

[arnabgangully]

Hi Ron,

I do not wanna challenge the accuracy of GMAT Prep. I know GMAT Questions are right , we should absorb the logic for it thats it.

Its my philosophy, but In this question if we know only the ratio of the transered Students like 33 % Males and 20% females and they totally makes 25% of the graduating students.

Then Are we not ignoring the relevent piece of information that is the present ratio of the Males and females in the college , which is mandatory to get a ratio for all the students graduating this Year.

Please comment.

I dont want to enter into any calculations as my common sense says its mandatory piece of information thats required to reach a solution.

[arnabgangully]

GMAT STaff,

Please reply to this as i think i am correct and want to enhance my learning if i am missing something.

Thanks,
Arnab

[arnabgangully]

What Wrong with my thought Process ?

[jlucero]

arnabgangully,

You're correctly stating the first piece of information, but thinking about the second equation as a ratio, rather than a second equation. Here's the math algebraically:

1/3m + 1/5f = 1/4t
m + f = t

We can calculate a ratio of males to females based on this, but I think you were ignoring the fact that all the males plus all the females give us the total number of students in the college. From these, you can calculate what fraction of the students are males (3/8).