Democrats and Republicans

[psm12se]

Guests at a recent congressional party contributed $15,000 to charity. Each guest who was neither a male nor a democrat contributed exactly $1,000. No amount was contributed by any guest who was a male, a democrat, or both. If half of the guests were democrats, how many guests attended the party?

1. The democrats attended the party at a rate of 2 males to every 3 females, half the rate for republicans.

2. 30% of the guests were democrat females.

[theCodeToGMAT]

1000xFR = 15000 ==> FR = 15

To find: MD+MR+FD+FR

Statement 1:
MD : FD = 2 : 3
MR : FR = 4 : 3
FR = 15 ==> MR = 20
MR + FR = 35 ==> G/2 = 35 = 70
SUFFICIENT

Statement 2:
30% of G = FD
INSUFFICIENT

Answer [spoiler]{A}[/spoiler]?

[Brent@GMATPrepNow]

I thought I'd point out that Rahul's approach is known as the Double Matrix Method. This technique can be used for most questions featuring a population in which each member has two characteristics associated with it.
Here, we have a population of guests, and the two characteristics are:
- Democrat or not Democrat
- Female or male

To learn more about this important technique, watch our free video: https://www.gmatprepnow.com/module/gmat- ... ems?id=919

Then try these additional practice questions that can be solved using the Double Matrix Method:
- https://www.beatthegmat.com/mba/2011/05/ ... question-1
- https://www.beatthegmat.com/mba/2011/05/ ... question-2
- https://www.beatthegmat.com/mba/2011/05/ ... question-3
- https://www.beatthegmat.com/ds-quest-t187706.html
- https://www.beatthegmat.com/overlapping- ... 83320.html
- https://www.beatthegmat.com/finance-majo ... 67425.html
- https://www.beatthegmat.com/ds-french-ja ... 22297.html
- https://www.beatthegmat.com/sets-t269449.html#692540
- https://www.beatthegmat.com/in-costume-f ... tml#692116

Cheers,
Brent

[GMATGuruNY]

Guests at a recent congressional party contributed $15,000 to charity. Each guest who was neither a male nor a democrat contributed exactly $1,000. No amount was contributed by any guest who was a male, a democrat, or both. If half of the guests were democrats, how many guests attended the party?

1. The democrats attended the party at a rate of 2 males to every 3 females, half the rate for republicans.

2. 30% of the guests were democrat females.

I posted an explanation for a very similar problem -- pretty much the same problem -- here:

https://www.beatthegmat.com/who-ate-the- ... 64828.html