• 5 Day FREE Trial
Study Smarter, Not Harder

Available with Beat the GMAT members only code

• FREE GMAT Exam
Know how you'd score today for $0 Available with Beat the GMAT members only code • Get 300+ Practice Questions 25 Video lessons and 6 Webinars for FREE Available with Beat the GMAT members only code • 1 Hour Free BEAT THE GMAT EXCLUSIVE Available with Beat the GMAT members only code • 5-Day Free Trial 5-day free, full-access trial TTP Quant Available with Beat the GMAT members only code • Award-winning private GMAT tutoring Register now and save up to$200

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

• Free Veritas GMAT Class
Experience Lesson 1 Live Free

Available with Beat the GMAT members only code

• Free Practice Test & Review
How would you score if you took the GMAT

Available with Beat the GMAT members only code

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

## A certain team has 12 members, including Joey. A three

tagged by: M7MBA

This topic has 2 expert replies and 0 member replies

### Top Member

M7MBA Moderator
Joined
29 Oct 2017
Posted:
325 messages
Followed by:
3 members
1

#### A certain team has 12 members, including Joey. A three

Sun Feb 18, 2018 4:42 am
A certain team has 12 members, including Joey. A three-member relay team will be selected as follows: one of the 12 members is to be chosen at random to run first, one of the remaining 11 members is to be chosen at random to run second, and one of the remaining 10 members is to be chosen at random to run third. What is the probability that Joey will be chosen to run second or third?

A. 1/1,320
B. 1/132
C. 1/110
D. 1/12
E. 1/6

The OA is the option E.

I don't understand this. Each time is random, isn't it? I am confused.

Experts, may you give me some help here? Please.

### GMAT/MBA Expert

Jeff@TargetTestPrep GMAT Instructor
Joined
09 Apr 2015
Posted:
1219 messages
Followed by:
14 members
39
Wed Feb 21, 2018 1:39 pm
M7MBA wrote:
A certain team has 12 members, including Joey. A three-member relay team will be selected as follows: one of the 12 members is to be chosen at random to run first, one of the remaining 11 members is to be chosen at random to run second, and one of the remaining 10 members is to be chosen at random to run third. What is the probability that Joey will be chosen to run second or third?

A. 1/1,320
B. 1/132
C. 1/110
D. 1/12
E. 1/6
The probability Joey will be chosen to run second is:

11/12 x 1/11 x 10/10 = 1/12

The probability Joey will be chosen to run third is:

11/12 x 10/11 x 1/10 = 1/12

Thus the probability that he will chosen to run second or third is:

1/12 + 1/12 = 2/12 = 1/6

_________________
Jeffrey Miller Head of GMAT Instruction

### GMAT/MBA Expert

Rich.C@EMPOWERgmat.com Elite Legendary Member
Joined
23 Jun 2013
Posted:
9606 messages
Followed by:
482 members
2867
GMAT Score:
800
Sun Feb 18, 2018 10:51 am
Hi M7MBA,

We're told that a certain team has 12 members, including Joey. A three-member relay team will be selected as follows: one of the 12 members is to be chosen at random to run first, one of the remaining 11 members is to be chosen at random to run second, and one of the remaining 10 members is to be chosen at random to run third. We're asked for the probability that Joey will be chosen to run second or third. There are a couple of different ways to do this type of math; here's how you can break the calculation down into two 'pieces':

The probability that Joey is chosen to run second is:
(Not Joey 1st)(Joey 2nd)(Not Joey 3rd) = (11/12)(1/11)(10/10) = 1/12

The probability that Joey is chosen to run third is:
(Not Joey 1st)(Not Joey 2nd)(Joey 3rd) = (11/12)(10/11)(1/10) = 1/12

Thus, the total probability of either event occurring is 1/12 + 1/12 = 2/12 = 1/6

GMAT assassins aren't born, they're made,
Rich

_________________
Contact Rich at Rich.C@empowergmat.com

### Top First Responders*

1 GMATGuruNY 93 first replies
2 Brent@GMATPrepNow 39 first replies
3 Jay@ManhattanReview 34 first replies
4 Rich.C@EMPOWERgma... 28 first replies
5 Scott@TargetTestPrep 11 first replies
* Only counts replies to topics started in last 30 days
See More Top Beat The GMAT Members

### Most Active Experts

1 GMATGuruNY

The Princeton Review Teacher

138 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

134 posts
3 Scott@TargetTestPrep

Target Test Prep

115 posts
4 Jeff@TargetTestPrep

Target Test Prep

104 posts
5 Max@Math Revolution

Math Revolution

92 posts
See More Top Beat The GMAT Experts