• Varsity Tutors
    Award-winning private GMAT tutoring
    Register now and save up to $200

    Available with Beat the GMAT members only code

    MORE DETAILS
    Varsity Tutors
  • e-gmat Exclusive Offer
    Get 300+ Practice Questions
    25 Video lessons and 6 Webinars for FREE

    Available with Beat the GMAT members only code

    MORE DETAILS
    e-gmat Exclusive Offer
  • Target Test Prep
    5-Day Free Trial
    5-day free, full-access trial TTP Quant

    Available with Beat the GMAT members only code

    MORE DETAILS
    Target Test Prep
  • EMPOWERgmat Slider
    1 Hour Free
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    EMPOWERgmat Slider
  • PrepScholar GMAT
    5 Day FREE Trial
    Study Smarter, Not Harder

    Available with Beat the GMAT members only code

    MORE DETAILS
    PrepScholar GMAT
  • Magoosh
    Magoosh
    Study with Magoosh GMAT prep

    Available with Beat the GMAT members only code

    MORE DETAILS
    Magoosh
  • The Princeton Review
    FREE GMAT Exam
    Know how you'd score today for $0

    Available with Beat the GMAT members only code

    MORE DETAILS
    The Princeton Review
  • Kaplan Test Prep
    Free Practice Test & Review
    How would you score if you took the GMAT

    Available with Beat the GMAT members only code

    MORE DETAILS
    Kaplan Test Prep
  • Veritas Prep
    Free Veritas GMAT Class
    Experience Lesson 1 Live Free

    Available with Beat the GMAT members only code

    MORE DETAILS
    Veritas Prep
  • Economist Test Prep
    Free Trial & Practice Exam
    BEAT THE GMAT EXCLUSIVE

    Available with Beat the GMAT members only code

    MORE DETAILS
    Economist Test Prep

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

This topic has 2 expert replies and 0 member replies

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

Post Thu Mar 01, 2018 5:42 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.

Experts, how can I solve this PS question? The first time, the probability that Joey wouldn't be chosen is 11/12? Or how should I start the solution?

  • +1 Upvote Post
  • Quote
  • Flag
Top Reply
Post Fri Mar 02, 2018 10:07 am
VJesus12 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

Answer: E

_________________
Scott Woodbury-Stewart Founder and CEO

  • +1 Upvote Post
  • Quote
  • Flag

GMAT/MBA Expert

Post Thu Mar 01, 2018 10:53 am
Hi VJesus12,

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

Final Answer: E

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

_________________
Contact Rich at Rich.C@empowergmat.com

  • +1 Upvote Post
  • Quote
  • Flag

Top First Responders*

1 GMATGuruNY 109 first replies
2 Brent@GMATPrepNow 44 first replies
3 Rich.C@EMPOWERgma... 37 first replies
4 Jay@ManhattanReview 25 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 image description GMATGuruNY

The Princeton Review Teacher

159 posts
2 image description Brent@GMATPrepNow

GMAT Prep Now Teacher

134 posts
3 image description Scott@TargetTestPrep

Target Test Prep

103 posts
4 image description Jeff@TargetTestPrep

Target Test Prep

94 posts
5 image description Rich.C@EMPOWERgma...

EMPOWERgmat

88 posts
See More Top Beat The GMAT Experts