statement 1: number of the teachers= 32
number of other employees=8

Statement 1 does not discuss anything about the employees who are vegetarians that drive hybrid gas-electric automobiles; not sufficient


Statement 2: 1. Half of all teachers are vegetarians and drive hybrid cars
2. number of teachers who are vegetarians and drive hybrid cars = 2 * number of other employees who are vegetarians and drive hybrid cars

since we are not given any number, we can not calculate any value based on one relationship; not sufficient

Combining both : number of teachers=32

Half of all teachers are vegetarians and drive hybrid cars
number of teachers who are vegetarians and drive hybrid cars= 16
number of teachers who are vegetarians and drive hybrid cars = 2 * number of other employees who are vegetarians and drive hybrid cars

number of other employees who are vegetarians and drive hybrid cars=16/2=8

the number of the employees who are vegetarians that drive hybrid gas-electric automobiles= 16+8
=24

Sufficient, Correct answer is C
+1 Kudos if you like the post

(1) Teachers account for 80% of the 40 employees.

We don’t have any information about preferences of those teachers. Insufficient.

(2) Half of all teachers are vegetarians and drive hybrid cars, exactly twice the number of other employees that do both.

Let’s denote # of teachers as T, and # of other employees as O.

Teachers who drive cars and are vegetarians = 1/2*T

Other employees who do both 1/2T=2Y, Y=1/4T

People who drive hybrid cars and are vegetarians at the same time will compose our intersection of two sets of T and O = 1/2T + 1/4T = 3/4T.

We have our intersection expressed through the number of teachers T, but we have no information about T. Insufficient.

(1)&(2) together: In order to solve (2) all that we need is # of teacher and that is provided by (1). Sufficient.

Answer D

As both statements together are sufficient to solve the question, correct answer should be C, not D.

+1 Kudos if you like the post

Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________