A local community club comprises of 15 members, all are standing in a

Question

A local community club comprises of 15 members, all of which are standing in a queue for the collection of their monthly coupons. Every third person from the back of the queue is a male. Are there less than 9 females in the queue?

(1) Every 3rd person from the front of the queue is a female.

(2) No two males are standing next to each other in the queue.

(1) Every 3rd person from the front of the queue is a female.

(2) No two males are standing next to each other in the queue.

amanvermagmat · Answer

Let M refers to male and F refers to female. So this is what the queue looks like:

Back) _, _, M, _, _, M, _, _, M, _, _, M, _, _, M (Front

(1) So this is what the queue looks like now:

Back) F, _, M, F, _, M, F, _, M, F, _, M, F, _, M (Front

Thus there are at least 5 females and at least 5 males in the queue. But still there are 5 places about which we dont know, so the total number of females could be greater or lesser than 9. Not sufficient.

(2) Since no two males are next to each other, any place adjacent to a male has to be occupied by a female. So we were given in the question:
Back) _, _, M, _, _, M, _, _, M, _, _, M, _, _, M (Front

From the front, now 2nd and 3rd places must be occupied by females (since these places are adjacent to a male). Similarly 5th, 6th, 8th, 9th, 11th, 12th and 14th. So the queue looks like this:

Back) _, F, M, F, F, M, F, F, M, F, F, M, F, F, M (Front
Except the last place, we know about other places, and that out of 14 other places, 9 are females are 5 are males. So the females are at least 9 in number, the answer to the question asked is NO. So this statement alone is sufficient.

Hence  B answer

bumpbot · Answer

Automated notice from GMAT Club BumpBot:

A member just gave Kudos to this thread, showing it’s still useful. I’ve bumped it to the top so more people can benefit. Feel free to add your own questions or solutions.

This post was generated automatically.

A local community club comprises of 15 members, all are standing in a

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Data Sufficiency (DS) Questions

A local community club comprises of 15 members, all are standing in a

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards