Data Sufficiency

What fraction of this year's graduating students at a certain college are males?

(1) Of this year's graduating class, 33 percent of the males and 20 percent of the females transferred from another college.
(2) Of this year's graduating students, 25 percent transferred from another college.

Let there be m males and f females. We need to find m/(m+f)

1) Clearly not enough

2) clearly not enough

1+2

0.33m + 0.20f = 0.25(m+f)

This gives us 8m - 5f = 0, which gives us the ratio between males and females. This is sufficient to calculate m/(m+f)

(C)

Right, I kiiinda see it, and was somewhat on that track, but it's still not clear in my head.

Can anyone else chime in with a more thorough answer, and maybe a strategy for how to deal with these types?

I think that part of what made this difficult for me was that I found the wording confusing.

joannabanana wrote:Right, I kiiinda see it, and was somewhat on that track, but it's still not clear in my head.

Can anyone else chime in with a more thorough answer, and maybe a strategy for how to deal with these types?

I think that part of what made this difficult for me was that I found the wording confusing.

Ok, heres another shot...

Let there be a total of m males, and f females in the graduating class. Thus, total number who graduated = m+f
We need to find the fraction of males from this, which means m/(m+f)

Now, lets look at 1

33% males and 20% females = (33/100)m + (20/200)f

Now, lets look at 2

25% of total students transferred from another colleged => (25/100)(m+f) transferred from another college.

Thus

0.33m + 0.20f = 0.25(m+f)

Multiply both sides by 100

33m + 20f = 25m + 25f
=> 8m= 5f => m = (5/8)f

Now, lets see if this is enough to find m/(m+f)

= (5/8)f/[(5/8)f + f]

= (5/8)f/(13/8)f = 5/13

Hence, the ratio is 5/13.

Hope that's a bit more clear

I also got confused by the wording... I assumed some of the students did not graduate from the class and hence picked E...