GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 23 Oct 2018, 16:22

### GMAT Club Daily Prep

#### Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# In a group, what percentage of members speak both french and English?

Author Message
TAGS:

### Hide Tags

Manager
Joined: 24 Jun 2017
Posts: 122
In a group, what percentage of members speak both french and English?  [#permalink]

### Show Tags

21 Nov 2017, 21:22
00:00

Difficulty:

25% (medium)

Question Stats:

67% (00:36) correct 33% (00:48) wrong based on 59 sessions

### HideShow timer Statistics

In a group, what percentage of members speak both french and English?

(1) 50% members speak English
(2) 80% members speak French
Manager
Joined: 24 Jun 2017
Posts: 122
Re: In a group, what percentage of members speak both french and English  [#permalink]

### Show Tags

21 Nov 2017, 21:27
Hi Guys
today I bumped into the following DS question (source Experts Global)
How do you think, does the answer fully correspond and respect GMAT DS logic?
I personally found it super confusing

Answer E, both statements are not sufficient. As we don't know how many members don't speak either of 2 languages so we can't determine
Math Expert
Joined: 02 Sep 2009
Posts: 50058
Re: In a group, what percentage of members speak both french and English?  [#permalink]

### Show Tags

21 Nov 2017, 21:30
cbh wrote:
In a group, what percentage of members speak both french and English?

(1) 50% members speak English
(2) 80% members speak French

General formula for two groups;
{Total} = {Group 1} + {Group 1} - {Both} + {Neither}

100 = 50 + 80 - {Both} + {Neither}

As, you can see without knowing {Neither} group we cannot answer the question.

19. Overlapping Sets

Hope it helps.
_________________
Manager
Joined: 24 Jun 2017
Posts: 122
Re: In a group, what percentage of members speak both french and English?  [#permalink]

### Show Tags

21 Nov 2017, 21:43
Bunuel wrote:
As, you can see without knowing {Neither} group we cannot answer the question.

Hope it helps.

I've already checked all those links and both formulas and I feel pretty confident with set questions.
So I can assume if I deal with DS set questions on test day, the question should always precise if there is someone in {Neither} group OR answer is E, right?
I was almost sure that GMAT doesn't trick candidates in that way...
Math Expert
Joined: 02 Sep 2009
Posts: 50058
Re: In a group, what percentage of members speak both french and English?  [#permalink]

### Show Tags

21 Nov 2017, 21:46
1
cbh wrote:
Bunuel wrote:
As, you can see without knowing {Neither} group we cannot answer the question.

Hope it helps.

I've already checked all those links and both formulas and I feel pretty confident with set questions.
So I can assume if I deal with DS set questions on test day, the question should always precise if there is someone in {Neither} group OR answer is E, right?
I was almost sure that GMAT doesn't trick candidates in that way...

I wouldn't call this a trick. This is natural and logical: of course there could be a group which does not speak any of the two languages, why not? Thinking otherwise would be assumption.
_________________
Manager
Joined: 20 Feb 2017
Posts: 166
Location: India
Concentration: Operations, Strategy
WE: Engineering (Other)
Re: In a group, what percentage of members speak both french and English?  [#permalink]

### Show Tags

21 Nov 2017, 21:48
Since Bunnel has posted there is no point in posting again but still this is my take
statement 1
insufficient . we don't know the percentage of french
statement 2
We don't know the percentage of English
insufficient
combine statement 1 and statement 2
when we have overlapping sets , it is necessary to know the condition if anything satisfies both the individual statements or if it satisfies neither .
Here 2 cases could be possible :
1. members who speak English also speak french or vice versa ( how will we know the information from given statements- insufficient)
2. members neither speaking English or french (we don't know about it either. hence insufficient)

_________________

If you feel the post helped you then do send me the kudos (damn theya re more valuable than \$)

Manager
Joined: 24 Jun 2017
Posts: 122
In a group, what percentage of members speak both french and English?  [#permalink]

### Show Tags

21 Nov 2017, 22:02
Bunuel wrote:
I wouldn't call this a trick. This is natural and logical: of course there could be a group which does not speak any of the two languages, why not? Thinking otherwise would be assumption.

awesome thanks. I got confused because I thought that in terms of GMAT, the "overlapping" nature of sets - it's an additional condition, that should be clarified in the question and if not shouldn't be taken into account. I mean, I can develop this logic further, we don't know if any member speaks any language but english and french. I mean that kind of problem is not an algebraic expression or calculus or geometry where you have clear although wide framework to operate within it and you don't have to make any assumptions that contradict that framework.
i will try to cover more set questions to catch on
In a group, what percentage of members speak both french and English? &nbs [#permalink] 21 Nov 2017, 22:02
Display posts from previous: Sort by