NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 12:54 It is currently 25 Apr 2024, 12:54
Decision Tracker
My Rewards
New posts
New comers' posts

Close
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
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel

At a certain school 25% of the students join a band, 25% play a sport

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
avatar
shinna
Intern
Intern
Joined: 03 Jan 2011
Posts: 9
Own Kudos [?]: 8 [3]
Given Kudos: 1
Send PM
At a certain school 25% of the students join a band, 25% play a sport [#permalink] New post   06 Nov 2011, 22:48
3
Bookmarks
00:00
A
B
C
D
E

Difficulty:

45% (medium)

Question Stats:

62% (01:36) correct 38% (01:39) wrong based on 97 sessions
Hide Show timer Statistics
At a certain school 25% of the students join a band, 25% play a sport and 20% both join the band and play a sport. if a randomly selected student is a member of the band, what is the probability that the student also plays a sport?

A. 3/4
B. 1/5
C. 2/5
D. 1/2
E. 4/5

Show Spoiler
I chose 2) 1/5 which is wrong. I took the 20% ( who play the sport and join the band ).
ShowHide Answer
Official Answer
E
User avatar
L
GyanOne
CEO
CEO
Joined: 24 Jul 2011
Status: World Rank #4 MBA Admissions Consultant
Posts: 3187
Own Kudos [?]: 1585 [1]
Given Kudos: 33
GMAT 1: 780 Q51 V48
GRE 1: Q170 V170
Send PM
Re: At a certain school 25% of the students join a band, 25% play a sport [#permalink] New post   06 Nov 2011, 23:12
1
Bookmarks
Expert Reply
This is the way to approach the question:
25% of the students join a band => 25% of the students either only join a band or both join a band and play sports
25% of the students play sports => 25% of the students either only play sports or both play sports and join a band

If a randomly selected student is a member of the band, then probability that the student also plays a sport = percentage of cases in which the student can do both/percentage of cases in which the student can just play sports or do both
=20%/25% = 4/5

The answer is therefore (E)
User avatar
synfist
Intern
Intern
Joined: 23 Nov 2009
Posts: 10
Own Kudos [?]: 4 [0]
Given Kudos: 0
Send PM
Re: At a certain school 25% of the students join a band, 25% play a sport [#permalink] New post   07 Nov 2011, 13:20
shinna wrote:
At a certain school 25% of the students join a band, 25% play a sport and 20% both join the band and play a sport. if a randomly selected student is a member of the band, what is the probablility that the student also plays a sport?

1) 3/4
2)1/5
3)2/5
4)1/2
5)4/5

I chose 2) 1/5 which is wrong. I took the 20% ( who play the sport and join the band ).


students joined band = 25%
students in both 20%

20/25 = 4/5
User avatar
kostyan5
Manager
Manager
Joined: 29 Oct 2011
Posts: 115
Own Kudos [?]: 349 [0]
Given Kudos: 19
Concentration: General Management, Technology
Schools: Sloan '16 (D)
GMAT 1: 760 Q49 V44
GPA: 3.76
Send PM
Re: At a certain school 25% of the students join a band, 25% play a sport [#permalink] New post   07 Nov 2011, 18:11
Number of students in band is 25%. 20% of them are also in sports. Probability is 20/25 = 4/5.
User avatar
L
ScottTargetTestPrep
Target Test Prep Representative
Joined: 14 Oct 2015
Status:Founder & CEO
Affiliations: Target Test Prep
Posts: 18761
Own Kudos [?]: 22052 [0]
Given Kudos: 283
Location: United States (CA)
Send PM
Re: At a certain school 25% of the students join a band, 25% play a sport [#permalink] New post   19 Mar 2018, 16:22
Expert Reply
shinna wrote:
At a certain school 25% of the students join a band, 25% play a sport and 20% both join the band and play a sport. if a randomly selected student is a member of the band, what is the probability that the student also plays a sport?

A. 3/4
B. 1/5
C. 2/5
D. 1/2
E. 4/5


We can let the number of students = 100.

We know that 25 join the band, 25 play a sport and 20 do both.

We are told that a randomly selected student is a band member, so we consider only the 25 students who are band members. Of those 25, we know that 20 play a sport. Thus, the probability that a student plays a sport, given that he joins a band is 20/25 = 4/5.

Answer: E
User avatar
bumpbot
Non-Human User
Joined: 09 Sep 2013
Posts: 32678
Own Kudos [?]: 822 [0]
Given Kudos: 0
Send PM
Re: At a certain school 25% of the students join a band, 25% play a sport [#permalink] New post   28 Dec 2023, 03:52
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
GMAT Club Bot
gmatclubot
Re: At a certain school 25% of the students join a band, 25% play a sport [#permalink]
28 Dec 2023, 03:52
Moderators:
Bunuel
Math Expert
92914 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions