In a club, 40 percent of the members are doctors and 70 percent are

Question

In a club, 40 percent of the members are doctors and 70 percent are non-engineers. What percent of those members who are not doctors are non-engineers?

A. 30
B. 43
C. 50
D. 72
E. none of these

siddhantvarma · Answer

Let's assume the total number of members in the club is 100 for easier calculation. (We can use any number, but 100 makes percentages easier to work with.)

Given information:
40% are doctors
70% are non-engineers

This means:
40 members are doctors
70 members are non-engineers
60 members are non-doctors (100 - 40 = 60)

The question asks: What percent of non-doctors are non-engineers?

To find this, we need to know:

How many non-doctors are non-engineers?

We can find this by subtracting the doctors from the total non-engineers:
70 (total non-engineers) - 40 (doctors) = 30 non-doctors who are non-engineers
Now, we can calculate the percentage:
(30 non-doctors who are non-engineers) / (60 total non-doctors) * 100 = 50%

Therefore, 50% of those who are not doctors are non-engineers.
The correct answer is C. 50.

KarishmaB · Answer

In a club, 40 percent of the members are doctors and 70 percent are non-engineers. What percent of those members who are not doctors are non-engineers?

A. 30
B. 43
C. 50
D. 72
E. none of these

Say there are 100 people in the club. 
Total 70 are non engineers so 30 are engineers.
40 are doctors (they are a part of the 70 of non engineers). So 60 are not doctors (these 60 include 30 engineers and 30 non engineers)

So non engineers are 30/60 * 100 = 50% of those who are not doctors.

Answer (C)

Aalto700 · Answer

What percent  of those members who are not doctors  are non-engineers?

Not doctor: 100-40 = 60. In which 60 people, include: enginer: 30 non- enginers: and 100-30-40 = 30 engineers. 
So % of non-engineers in those 60 people is 30/60 = 50%

Do I need to think about people who are both doctors and engineers?  Krunaal

Krunaal · Answer

I think this question could've multiple answers, unless there’s an assumption that someone cannot be both a doctor and an engineer, below are the two answers I got, please let me know if there's a flaw in the question or a miss in my understanding or approach Bunuel / KarishmaB

	D	ND	T
E	0	30	30
NE	40	30	70
T	40	60	100

Answer: 30/60

	D	ND	T
E	20	10	30
NE	20	50	70
T	40	60	100

Answer: 50/60

D 
 ND 
 T 
 
  E 
 0 
 30 
 30 
 
  NE 
 40 
 30 
 70 
 
  T 
 40 
 60 
 100

Answer: 30/60

D 
 ND 
 T 
 
  E 
 20 
 10 
 30 
 
  NE 
 20 
 50 
 70 
 
  T 
 40 
 60 
 100

Answer: 50/60

KarishmaB · Answer

Krunaal  - I would assume doctors and engineers are mutually exclusive sets. In my mind it is justified (the way we assume male and female sets are mutually exclusive) though a case may be made otherwise. Even though this is not an official question, I would make the same assumption in actual GMAT too. Just like they expect us to know that Biology is a Science, I would expect that they would want us to make this distinction too.

HarshavardhanR · Answer

https://gmatclub.com/forum/download/file.php?id=89450

I think the intent here is that a doctor cannot be an engineer. An engineer cannot be a doctor. 
---
Harsha

In a club, 40 percent of the members are doctors and 70 percent are

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