BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

one more in probability

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Tue Nov 25, 2008 7:16 am
Location: chennai
by Gopaleie2k4 » Tue Nov 25, 2008 12:05 pm
In a survey for 248 people,156 are married,70 are self employed and 25 percent of those who married are self employed.if a person is to be randomly selected from those sureveyed.what is the probability that the person selected will be self employed but not married ?

Ans. 1/8

Need explanation pls.
Thanks
Gopal
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Senior | Next Rank: 100 Posts
Posts: 95
Joined: Fri Sep 28, 2007 10:16 am
Thanked: 6 times
GMAT Score:710

Re: one more in probability

by muzali » Tue Nov 25, 2008 2:40 pm
Gopaleie2k4 wrote:In a survey for 248 people,156 are married,70 are self employed and 25 percent of those who married are self employed.if a person is to be randomly selected from those sureveyed.what is the probability that the person selected will be self employed but not married ?

Ans. 1/8

Need explanation pls.
total people = 248
Married (selfemployed + not selfemployed) = 156
25% of married are selfemployed, so this number is (25/100)*156 =39
self employed people total = 70
so self employed people who are not married = 70-39 = 31
Required probability = 31/248 = 1/8
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Senior | Next Rank: 100 Posts
Posts: 35
Joined: Wed Oct 01, 2008 3:55 pm
Thanked: 6 times

by rmpaes » Tue Nov 25, 2008 11:21 pm
We can use a table to organize information given in otherwise confusing overlapping problem sets. We just carefully fill in the chart with the info.



---------------------self employed-------not self employed--------total
married---------------39----------------------------------------------156
not married-----------31-------------------------------------------------
total-------------------70---------------------------------------------------


We are told :25 percent of those who married are self employed. Thus,
156* 1/4 = 39. We can easily find out those not married and self employed by subtracting the total of those self employed from those that are married. This gives us 31.

So the
probability that the person selected will be self employed but not married = 31/248 = 1/8
700+ your target then check out my 800 gmat blog here:
https://800gmatblog.zoxic.com
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 833
Joined: Mon Aug 04, 2008 1:56 am
Thanked: 13 times

abs

by vivek.kapoor83 » Wed Nov 26, 2008 2:22 am
I drew Venn Diagram..Hope it helps !!!!!
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Thu Mar 25, 2010 11:35 pm

by cwbeemer » Tue May 11, 2010 1:09 pm
I got confused when trying to find the probability because I thought that you had to find the probability that the person chosen would be 1st not married AND self employed.

So I did the following

(not married/total) * (self employed/total not married)
which is the same as (92/248) * 31/92)

I didn't know that I could just put self employed/total

Can you please expalin
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1