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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

probability that exactly 2 will buy

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 621
Joined: Wed Apr 09, 2008 7:13 pmFollowed by: 4 members
Thanked: 33 times
by vittalgmat » Thu Jan 01, 2009 1:56 am
The probability that a visitor at the mall buys a pack of candy is 30%. If three visitors come to the mall today, what is the probability that exactly two will buy a pack of candy?


A. 0.343
B. 0.147
C. 0.189
D. 0.063
E. 0.027


[spoiler]OA: C[/spoiler]

Thanks
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 424
Joined: Sun Dec 07, 2008 5:15 pm
Location: Sydney
Thanked: 12 times

by piyush_nitt » Thu Jan 01, 2009 3:32 am
Probability that visitor buys candy P(A)= .3
Probability that visitor NOT buys candy P(!A) = .7

Probability that Exactly 2 visitors buy candy (say A, B, C are visitors) =

P(!A)P(B)P(C)+ P(A)P(!B)P(C)+ P(A)P(B)P(!C) = .7.3.3+ .3.7.3+.3.3.7 = .189
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pmFollowed by: 25 members
Thanked: 237 times
GMAT Score:730

Re: probability that exactly 2 will buy

by logitech » Thu Jan 01, 2009 11:01 am
"two will buy a pack of candy" BUY BUY NOTBUY can be selected in 3C2=3 ways

each time it is 3/10 x 3/10 x 7/10 ( 1-[3/10] = 7/10 the probability of NOT buying )

So we will have 3 scenaroius with the same probability

3 x 3 x 3 x 7 / 10 x 10 x 10 = 9/10 x 10 x 21 /10 = 9x2.1/100 = 0.189
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1