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 Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

Target question:How many are doctors who have a law degree?

Given: There are 50 people

When I scan the two statements, I see that we have the ingredients for applying 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 (aka overlapping sets questions). Here, we have a population of 50 people, and the two characteristics are: - Doctor or NOT a doctor - Has law degree or doesn't have law degree

So, we can set up our double matrix as follows: NOTE: I have placed a star in the box that represents doctors who have a law degree, since this is what the target question is asking us about

Statement 1: In the group, 36 people are doctors. If the group has 50 people, and 36 are doctors, we can conclude that there are 14 non-doctors in the group. Let's add this information to our matrix:

As you can see, there's no way to determine the value that must go in the starred box. As such, statement 1 is NOT SUFFICIENT

Statement 2: In the group, 18 people have a law degree If 18 of the 50 people have a law degree, than the remaining 32 people do NOT have a law degree. Let's add this information to our matrix:

As you can see, there's no way to determine the value that must go in the starred box. As such, statement 2 is NOT SUFFICIENT

Statements 1 and 2 combined When we combine the two statements, we get the following:

There are several ways to complete this matrix. Here are two cases:

case a: In this case, there are 10 doctors with law degrees.

case a: In this case, there are 5 doctors with law degrees. Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Re: In a certain group of 50 people, how many are doctors who have a law [#permalink]

Show Tags

26 Jun 2017, 14:01

In a certain group of 50 people, how many are doctors who have a law degree?

Total No. Of People = 50

(1) In the group, 36 people are doctors.

This tells us that there are 36 Doctors, however this does not give us any information on whether they have a law degree or no

Total = 50 Doc = 36 Non-Doc = 14

Hence, (1) =====> is NOT SUFFICIENT

(2) In the group, 18 people have a law degree.

This tells us that there are 18 people who are having law degree, however, it does not provide us any information on whether they are doctors or non-doctors

Total = 50 Law Degree = 18 Non-Law Degree = 32

Hence, (2) =====> is NOT SUFFICIENT

Combining (1) and (2) we get:

Total = 50 Doc = 36 Non-Doc = 14

Total = 50 Law Degree = 18 Non-Law Degree = 32

Even after combining we are not aware of how many doctors are having a law degree as they are two exclusive sets with no connection provided.

We can have doctors falling under "Law Degree" or "Non-Law Degree" or BOTH as we are not aware of this distribution we will not be able to answer this question.

Hence, Answer is E _________________

"Nothing in this world can take the place of persistence. Talent will not: nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not: the world is full of educated derelicts. Persistence and determination alone are omnipotent."

Best AWA Template: https://gmatclub.com/forum/how-to-get-6-0-awa-my-guide-64327.html#p470475

In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

The question is very simple but it has a small pitfall - some test takers will certainly answer (C) and move on. When we read "Doctors who have a law degree", we immediately think of the intersection of the two sets - doctors and lawyers.

So what might come to mind is Total = n(D) + n(L) - n(D and L)

Here is the catch: we don't have the total i.e. the union of the two sets. 50 people is just a certain group. It is not necessary that each one of them is certainly a doctor or a lawyer or both. In effect, we do not have the number of "neither".

Re: In a certain group of 50 people, how many are doctors who have a law [#permalink]

Show Tags

03 Jul 2017, 00:53

Of course neither statement alone is sufficient. when we combine, we get that out of 50, 36 are doctors and 18 have a law degree.

But we don't know how many have neither degree. without that info we cant say how many have both degrees. Say 'x' people have both degrees, then: 36-x are only doctors, 18-x are only lawyers. People having at least one degree = 36-x + x + 18-x = 54 - x, and those having neither degree are: 50 - (54-x) = x-4.

Until we know the value of (x-4) we cant find 'x'. So insufficient. Answer is E

Re: In a certain group of 50 people, how many are doctors who have a law [#permalink]

Show Tags

10 Jul 2017, 14:18

sashiim20 wrote:

Bunuel wrote:

In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

Total number of people in the group \(= 50\)

(1) In the group, 36 people are doctors.

Number of doctors \(= 36\)

Number of not doctors \(= 50 - 36 = 14\)

We cannot find Doctors with law degree. Hence I is Not Sufficient.

(2) In the group, 18 people have a law degree.

Number of people with law degrees \(= 18\)

Number of people without law degrees \(= 50 - 18 = 32\)

We cannot find Doctors with law degree. Hence II is Not Sufficient.

Combining (1) and (2);

Total = 50

Number of doctors = 36

Number of people with law degree = 18.

We cannot find Doctors with law degree. Answer (E)...

To add to it, If we use the formula : Total - neither = D + L - (D&L) We have Total, We have D, We have L, But we cant find (D&L) until we have 'neither'.

Re: In a certain group of 50 people, how many are doctors who have a law [#permalink]

Show Tags

10 Jul 2017, 14:21

VeritasPrepKarishma wrote:

Bunuel wrote:

In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

The question is very simple but it has a small pitfall - some test takers will certainly answer (C) and move on. When we read "Doctors who have a law degree", we immediately think of the intersection of the two sets - doctors and lawyers.

So what might come to mind is Total = n(D) + n(L) - n(D and L)

Here is the catch: we don't have the total i.e. the union of the two sets. 50 people is just a certain group. It is not necessary that each one of them is certainly a doctor or a lawyer or both. In effect, we do not have the number of "neither".

Hence, answer here will be (E).

Hi Karishma,

I think the correct approach would be to use Total - neither = n(D) + n(L) - n(D and L), instead of Total = n(D) + n(L) - n(D and L)

In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

The question is very simple but it has a small pitfall - some test takers will certainly answer (C) and move on. When we read "Doctors who have a law degree", we immediately think of the intersection of the two sets - doctors and lawyers.

So what might come to mind is Total = n(D) + n(L) - n(D and L)

Here is the catch: we don't have the total i.e. the union of the two sets. 50 people is just a certain group. It is not necessary that each one of them is certainly a doctor or a lawyer or both. In effect, we do not have the number of "neither".

Hence, answer here will be (E).

Hi Karishma,

I think the correct approach would be to use Total - neither = n(D) + n(L) - n(D and L), instead of Total = n(D) + n(L) - n(D and L)

Please note: "... what might come to mind is Total = n(D) + n(L) - n(D and L)" "Here is the catch:... we do not have the number of neither"

The point is we use Total as the union of two sets very often and hence might forget "neither".
_________________

Re: In a certain group of 50 people, how many are doctors who have a law [#permalink]

Show Tags

12 Jul 2017, 03:27

Bunuel wrote:

In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

Total = 50 Docs who have law degrees = ?

1) 36 are docs 14 are not docs. Law degrees= ? Insufficient.

2) 18 have law degree. 32 have no law degree. # of docs = ? Insufficient.

1+2) # of doctors = 36 # of law degree = 18 Either 18 doctors have law degrees, or 14 non-docs have law degrees, and 4 doctors have law degrees. Other variations are also possible. Insufficient.

Re: In a certain group of 50 people, how many are doctors who have a law [#permalink]

Show Tags

12 Jul 2017, 04:12

VeritasPrepKarishma wrote:

ashygoyal wrote:

VeritasPrepKarishma wrote:

[quote="Bunuel"]In a certain group of 50 people, how many are doctors who have a law degree?

(1) In the group, 36 people are doctors. (2) In the group, 18 people have a law degree.

The question is very simple but it has a small pitfall - some test takers will certainly answer (C) and move on. When we read "Doctors who have a law degree", we immediately think of the intersection of the two sets - doctors and lawyers.

So what might come to mind is Total = n(D) + n(L) - n(D and L)

Here is the catch: we don't have the total i.e. the union of the two sets. 50 people is just a certain group. It is not necessary that each one of them is certainly a doctor or a lawyer or both. In effect, we do not have the number of "neither".

Hence, answer here will be (E).

Hi Karishma,

I think the correct approach would be to use Total - neither = n(D) + n(L) - n(D and L), instead of Total = n(D) + n(L) - n(D and L)

Please note: "... what might come to mind is Total = n(D) + n(L) - n(D and L)" "Here is the catch:... we do not have the number of neither"

The point is we use Total as the union of two sets very often and hence might forget "neither".[/quote] Sorry, I think my last reply lacked detail ! My point was, When you combine both statements.. U will observe, u have the following info: N(total) N(doctors) N(law degree holders)

At this point if you use: N(total) = n(docs) + n(law) - n(both)

Then u r surely gonna fall in the 'C Trap' because u will think, u have got 3 values from question and u can easily find 4th one.

But, if you had the correct formula in mind, i.e. N(total)- neither= n(doc) +n(law) - n(both)

You will realise that, u still have two values missing. Without the 'neither' u cant find n(both). Hence, info.is incomplete and answer is E.

So my point was, always have the formula (which involves 'neither') in your mind !

Hope I was able to put forward my part of understanding. Please correct me if my thought process is wrong.