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

 It is currently 14 Dec 2019, 06:30

### 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

# At a certain health club, 30% of the members use both pool a

Author Message
TAGS:

### Hide Tags

Manager
Joined: 13 Aug 2009
Posts: 110
WE 1: 4 years in IT
At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

Updated on: 21 May 2017, 14:08
1
10
00:00

Difficulty:

35% (medium)

Question Stats:

69% (02:02) correct 31% (02:26) wrong based on 247 sessions

### HideShow timer Statistics

At a certain health club, 30 percent of the members use both the pool and sauna, but 40 percent of the members who use the pool do not use the sauna. What percent of the members of the health club use the pool?

A. 33 1/3%
B. 40%
C. 50%
D. 62 1/2%
E. 75%

Attachment:

Percent.JPG [ 15.42 KiB | Viewed 6303 times ]

Originally posted by raghavs on 07 Mar 2010, 10:25.
Last edited by Bunuel on 21 May 2017, 14:08, edited 2 times in total.
Renamed the topic, edited the question and added the OA.
Manager
Joined: 30 Aug 2009
Posts: 217
Location: India
Concentration: General Management
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

07 Mar 2010, 11:21
1
raghavs wrote:
help me to get this.

well the wording is confusing (atleast to me )

giving it a try

P = pool S = sauna
given P+S = 30 then let only S be x and only P will be 100 - (30+x) = 70 -x
40% of (70-x) = x => 28 - 0.4x = x => x = 20% so only P = 70 -x = 50%
Manager
Joined: 22 Dec 2009
Posts: 242
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

08 Mar 2010, 14:16
4
raghavs wrote:
help me to get this.

Its given 30% use both pool and suana.

Also it is given 40% of the pool do not use sauna. Therefore 60% of the people who use pool also use sauna.

Let total no of members be 100
members using both pool & sauna = 30

Let no of members using Pool be p

60% of p = 30
p = 50
Therefore.. members using only Sauna = 100 -50 = 50
Director
Status: Everyone is a leader. Just stop listening to others.
Joined: 22 Mar 2013
Posts: 699
Location: India
GPA: 3.51
WE: Information Technology (Computer Software)
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

15 Apr 2014, 03:39
This problem belongs to overlapping sets not to percentage and interest.
by using tabular method with row : pool -- nopool and column: sauna | nosauna and by assuming total of members=100, one can easily solve this problem.
Intern
Joined: 23 Mar 2014
Posts: 11
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

27 Apr 2014, 13:05
1
This question got me - I misunderstood the fact that 40% represents all people using the pool and the 30% represent the entire club members.

I'm trying to figure it out in another way to help me understand (although the overlapping sets method with the tables is probably the best)...

1. Let's assume that a total of 100 people use the pool.
2. From the question, 40% of them use the pool ONLY meaning 0.4 x 100 = 40 people. This means that 100-40=60 people uses the pool and sauna.
3. Also from the question, 30% of the ENTIRE CLUB uses the pool and sauna. If the 60 people from step 2 above uses the pool and sauna represents 30% of the entire club, that means there are 200 people in the club.
4. To find percentage of ALL people using the pool - 100/200 = 50%
Intern
Joined: 12 May 2013
Posts: 46
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

28 Apr 2014, 06:42
raghavs wrote:
At a certain health club, 30 percent of the members use both the pool and sauna, but 40 percent of the members who use the pool do not use the sauna. What percent of the members of the health club use the pool?

A. 33 1/3%
B. 40%
C. 50%
D. 62 1/2%
E. 75%

i still find the question unclear
thank you
Math Expert
Joined: 02 Sep 2009
Posts: 59724
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

28 Apr 2014, 10:43
raghavs wrote:
At a certain health club, 30 percent of the members use both the pool and sauna, but 40 percent of the members who use the pool do not use the sauna. What percent of the members of the health club use the pool?

A. 33 1/3%
B. 40%
C. 50%
D. 62 1/2%
E. 75%

i still find the question unclear
thank you

40 percent of the members who use the pool do not use the sauna, hence the remaining 60 percent of the members who use the pool use the sauna. So, 60 percent of the members who use the pool use both pool and sauna. So, 0.6*{pool} = {both}.

We also know that 30 percent of the members use both the pool and sauna: 0.3*{total} = {both}.

Equate: 0.6*{pool} = 0.3*{total} --> {pool}/{total} = 0.5.

Hope it's clear.
_________________
Manager
Joined: 11 Feb 2017
Posts: 181
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

12 Jul 2017, 09:02
Bunuel wrote:
raghavs wrote:
At a certain health club, 30 percent of the members use both the pool and sauna, but 40 percent of the members who use the pool do not use the sauna. What percent of the members of the health club use the pool?

A. 33 1/3%
B. 40%
C. 50%
D. 62 1/2%
E. 75%

i still find the question unclear
thank you

40 percent of the members who use the pool do not use the sauna, hence the remaining 60 percent of the members who use the pool use the sauna

BUT THOSE 60% must contain people who do not use the pool and only use sauna?
Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8701
Location: United States (CA)
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

16 Jul 2017, 17:25
raghavs wrote:
At a certain health club, 30 percent of the members use both the pool and sauna, but 40 percent of the members who use the pool do not use the sauna. What percent of the members of the health club use the pool?

A. 33 1/3%
B. 40%
C. 50%
D. 62 1/2%
E. 75%

We can let the total number of members = 100 and x = the number of members who use the pool.

Thus, we have 30 members who use both the pool and sauna. Since 40 percent of the members who use the pool do not use the sauna, we know that 60 percent of the members who use the pool also use the sauna, and we already know that this number is 30. Thus, we can create the following equation:

0.6x = 30

x = 30/0.6 = 300/6 = 50

Thus, 50/100 = 50% of the members use the pool.

_________________

# Scott Woodbury-Stewart

Founder and CEO

Scott@TargetTestPrep.com
122 Reviews

5-star rated online GMAT quant
self study course

See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews

If you find one of my posts helpful, please take a moment to click on the "Kudos" button.

Senior Manager
Joined: 15 Jan 2017
Posts: 332
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

24 Jul 2017, 09:13
One way to look at this:
- 40 = pool
- 30 = pool + sauna
- 60 = sauna (100 minus 40)

so how many pool? Pool users total = pool + pool - (pool+sauna overlap) => 40 + (40 - 30) = 50%
Intern
Joined: 01 Dec 2018
Posts: 43
Re: At a certain health club, 30% of the members use both pool a  [#permalink]

### Show Tags

07 Aug 2019, 01:08
Hi!Can someone make a table for this one ?
Re: At a certain health club, 30% of the members use both pool a   [#permalink] 07 Aug 2019, 01:08
Display posts from previous: Sort by