• 5 Day FREE Trial
Study Smarter, Not Harder

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

• Free Trial & Practice Exam
BEAT THE GMAT EXCLUSIVE

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

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

Available with Beat the GMAT members only code

• 1 Hour Free
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

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

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 problem - how did Princeton Review solve this?

This topic has 3 member replies
maxim730 Senior | Next Rank: 100 Posts
Joined
26 Dec 2006
Posted:
76 messages
Followed by:
2 members

#### Probability problem - how did Princeton Review solve this?

Wed Dec 27, 2006 3:25 pm
I can't figure out how Princeton Review solved the below problem, their explanation doesn't make sense to me.

If anyone can break it down, that would be great!!

Q:

Ten strips of paper are numbered 1 to 10 and placed in a bag. If three numbers are drawn from the bag at random, what is the probability that the sum of the numbers drawn will be odd?

A) 1/12
B) 5/36
C) 15/36
D) 1/2
E) 11/18

OA is D

Princeton explanation (This is an image I added, I didn't want to type it out_):

http://img143.imageshack.us/my.php?image=problemzn4.jpg

Need free GMAT or MBA advice from an expert? Register for Beat The GMAT now and post your question in these forums!
thankont Senior | Next Rank: 100 Posts
Joined
15 Dec 2006
Posted:
41 messages
Followed by:
1 members
Top Reply
Fri Dec 29, 2006 10:52 pm
Mark can we just simply say that since there are same number of odd and even numbers from 1 - 10 (5 each), and since odd number can be formed the same number of ways as an even number then right away p=1/2 ?

maxim730 Senior | Next Rank: 100 Posts
Joined
26 Dec 2006
Posted:
76 messages
Followed by:
2 members
Top Reply
Thu Dec 28, 2006 6:49 am
That makes sense, thanks Mark!

thankont Senior | Next Rank: 100 Posts
Joined
15 Dec 2006
Posted:
41 messages
Followed by:
1 members
Fri Dec 29, 2006 10:52 pm
Mark can we just simply say that since there are same number of odd and even numbers from 1 - 10 (5 each), and since odd number can be formed the same number of ways as an even number then right away p=1/2 ?

### Best Conversation Starters

1 lheiannie07 116 topics
2 LUANDATO 68 topics
3 swerve 65 topics
4 ardz24 65 topics
5 Roland2rule 64 topics
See More Top Beat The GMAT Members...

### Most Active Experts

1 Scott@TargetTestPrep

Target Test Prep

198 posts
2 Brent@GMATPrepNow

GMAT Prep Now Teacher

181 posts
3 Jeff@TargetTestPrep

Target Test Prep

168 posts
4 Rich.C@EMPOWERgma...

EMPOWERgmat

134 posts
5 GMATGuruNY

The Princeton Review Teacher

119 posts
See More Top Beat The GMAT Experts