• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

Available with Beat the GMAT members only code

• Magoosh
Study with Magoosh GMAT prep

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

• 5 Day FREE Trial
Study Smarter, Not Harder

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

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

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

• 1 Hour Free
BEAT THE GMAT EXCLUSIVE

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

## Probability

tagged by: Brent@GMATPrepNow

This topic has 4 expert replies and 0 member replies

### Top Member

Roland2rule Master | Next Rank: 500 Posts
Joined
30 Aug 2017
Posted:
392 messages
Followed by:
1 members

#### Probability

Sat Sep 16, 2017 7:26 pm
Joshua and Jose work at an auto repair center with 4 other workers. For a survey on health care insurance, 2 of the 6 workers will be randomly chosen to be interviewed. What is the probability that Joshua and Jose will both be chosen?

A. 1/15
B. 1/12
C. 1/9
D. 1/6
E. 1/3

OA is a

why is E the only best option? which probability approach did you use to get your answer?[/spoiler]

Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!

### GMAT/MBA Expert

Matt@VeritasPrep GMAT Instructor
Joined
12 Sep 2012
Posted:
2640 messages
Followed by:
113 members
625
Target GMAT Score:
V51
GMAT Score:
780
Sun Sep 17, 2017 5:12 pm
It seems like this is easy conceptually too. We want to pick both guys, so there's only one way to do that: 2 choose 2. If we're just picking two random guys, there are 6 choose 2, or 15 ways to do that, as shown in my previous post.

From there:

Our target = the one group
Our total = 6 choose 2 = 15 groups

Probability = target/total = 1/15

Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

### GMAT/MBA Expert

Matt@VeritasPrep GMAT Instructor
Joined
12 Sep 2012
Posted:
2640 messages
Followed by:
113 members
625
Target GMAT Score:
V51
GMAT Score:
780
Sun Sep 17, 2017 5:10 pm
We could also do All Groups - Groups With Neither Guy - Groups With Only One of the Guys:

All Groups = 6 choose 2 = 6!/(4!2!) = 15
Neither Guy = 4 choose 2 = 4!/(2!2!) = 6
Only One Guy = (4 choose 1) * (2 choose 1) = 8

If Only One Guy doesn't make sense, I'm choosing one of the other four people first, then choosing one of our two guys to go with them.

That leaves us with 15 - 6 - 8 = 1 group with both guys. 1 group out of 15 is 1/15, and we're done.

Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

### GMAT/MBA Expert

Matt@VeritasPrep GMAT Instructor
Joined
12 Sep 2012
Posted:
2640 messages
Followed by:
113 members
625
Target GMAT Score:
V51
GMAT Score:
780
Sun Sep 17, 2017 5:12 pm
It seems like this is easy conceptually too. We want to pick both guys, so there's only one way to do that: 2 choose 2. If we're just picking two random guys, there are 6 choose 2, or 15 ways to do that, as shown in my previous post.

From there:

Our target = the one group
Our total = 6 choose 2 = 15 groups

Probability = target/total = 1/15

Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

### GMAT/MBA Expert

Matt@VeritasPrep GMAT Instructor
Joined
12 Sep 2012
Posted:
2640 messages
Followed by:
113 members
625
Target GMAT Score:
V51
GMAT Score:
780
Sun Sep 17, 2017 5:10 pm
We could also do All Groups - Groups With Neither Guy - Groups With Only One of the Guys:

All Groups = 6 choose 2 = 6!/(4!2!) = 15
Neither Guy = 4 choose 2 = 4!/(2!2!) = 6
Only One Guy = (4 choose 1) * (2 choose 1) = 8

If Only One Guy doesn't make sense, I'm choosing one of the other four people first, then choosing one of our two guys to go with them.

That leaves us with 15 - 6 - 8 = 1 group with both guys. 1 group out of 15 is 1/15, and we're done.

Enroll in a Veritas Prep GMAT class completely for FREE. Wondering if a GMAT course is right for you? Attend the first class session of an actual GMAT course, either in-person or live online, and see for yourself why so many students choose to work with Veritas Prep. Find a class now!

### Best Conversation Starters

1 lheiannie07 120 topics
2 LUANDATO 62 topics
3 swerve 62 topics
4 ardz24 61 topics
5 AAPL 57 topics
See More Top Beat The GMAT Members...

### Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

174 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

173 posts
3 Rich.C@EMPOWERgma...

EMPOWERgmat

131 posts
4 Jeff@TargetTestPrep

Target Test Prep

130 posts
5 EconomistGMATTutor

The Economist GMAT Tutor

130 posts
See More Top Beat The GMAT Experts