Hamburgers problem .. Need help

This topic has expert replies
Senior | Next Rank: 100 Posts
Posts: 63
Joined: Sat Jul 24, 2010 10:29 am
Thanked: 1 times
Followed by:1 members
GMAT Score:640

Hamburgers problem .. Need help

by praveen_gmat » Sun Aug 22, 2010 10:07 pm
Guests at a recent party ate a total of fifteen hamburgers. Each guest who was neither a student nor a
vegetarian ate exactly one hamburger. No hamburger was eaten by any guest who was a student, a
vegetarian, or both. If half of the guests were vegetarians, how many guests attended the party?

(1) The vegetarians attended the party at a rate of 2 students to every 3 non-students, half the rate for
non-vegetarians.

(2) 30% of the guests were vegetarian non-students.
Source: — Data Sufficiency |

User avatar
Master | Next Rank: 500 Posts
Posts: 158
Joined: Wed Jun 16, 2010 8:21 am
Thanked: 13 times
Followed by:1 members

by rohit_gmat » Mon Aug 23, 2010 1:37 am
praveen_gmat wrote:Guests at a recent party ate a total of fifteen hamburgers. Each guest who was neither a student nor a
vegetarian ate exactly one hamburger. No hamburger was eaten by any guest who was a student, a
vegetarian, or both. If half of the guests were vegetarians, how many guests attended the party?

(1) The vegetarians attended the party at a rate of 2 students to every 3 non-students, half the rate for
non-vegetarians.

(2) 30% of the guests were vegetarian non-students.

I kinda broke it down like this :
STU VEG #(of hamburgers)
N N 1 (each)
N Y 0
Y N 0
Y Y 0
"No hamburger was eaten by any guest who was a student, a vegetarian, or both"

Since 15 hamburgers were eaten...

STU VEG #(of ppl)
N N 15
N Y x
Y N y
Y Y z

15 + y = x + z (half the guests were vegetarians)


Stmnt 1)
z/x = 2/3
y/15 = 4/3 (half the rate)

This helps us solve for y, giving us x+z as well and the total number of guests as well : SUFFICIENT


Stmnt 2)

x = 0.3 * (x+y+z+15)

INSUFFICIENT

Will go with A....

not sure tho....