Data Sufficiency

All the members of club Y are either Democrats or Repulicans. If 1/2 of the male members and 3/5 of the female members are Democrats, what is the ratio of the number of males to the number of females in the club?

(1) In club Y the number of females members is one less than the number of male members.

(2) In club Y the number of male Republican members is equal to the number of female Democratic members.

I think the answer is B. Because from statement 2 we can get the ratio of m/f.

Yes, the correction answer is B. Can you explain this further?

madsport wrote:All the members of club Y are either Democrats or Repulicans. If 1/2 of the male members and 3/5 of the female members are Democrats, what is the ratio of the number of males to the number of females in the club?

(1) In club Y the number of females members is one less than the number of male members.

(2) In club Y the number of male Republican members is equal to the number of female Democratic members.

We want to solve for m/f.

(1) f = m - 1

No way to get m/f out of this: insufficient.

(2) Male(rep) = Female(Dem)

Well, if 1/2 of the males are democrats, then half are republicans. So, (2) tells us that:

(1/2)m = (3/5)f

We can certainly rearrange this to solve for m/f: sufficient.

(2) is sufficient, (1) isn't: choose (B).

As an aside, here's the math for (2):

(1/2)m = (3/5)f
(1/2)m / f = (3/5)
m/f = (3/5)/(1/2)
m/f = (3/5)*(2/1)
m/f = 6/5

Of course, we never actually want to do the math if we can avoid it - as soon as you can see that our equation can be manipulated to

m/f=some number

you know you have enough information to solve.