Please help (Probability w. dice)

Oldest

Best Reply

Author

Message

TAGS:

Intern

Joined: 01 Jun 2010

Posts: 5

Followers: 0

Kudos [?]: 0 [0], given: 0

Please help (Probability w. dice) [#permalink]

07 Jun 2010, 07:57

00:00

Question Stats:

100% (01:32) correct

0% (00:00) wrong

based on 1 sessions

When two dice are thrown, what is the probability that the score on the second dice is higher than the score on the first dice?

[Reveal] Spoiler:

5/12

Please explain

Intern

Joined: 01 Jun 2010

Posts: 5

Followers: 0

Kudos [?]: 0 [0], given: 0

Re: Please help (Probability w. dice) [#permalink]

07 Jun 2010, 08:03

I understand now :-D

1) First dice: 1 ... Second dice: 2, 3, 4, 5, or 6 ... P=(1/6)*(5/6)
2) First dice: 2 ... Second dice: 3, 4, 5, or 6 ... P=(1/6)*(4/6)
3) First dice: 3 ... Second dice: 4, 5, or 6 ... P=(1/6)*(3/6)
4) First dice: 4 ... Second dice: 5 or 6 ... P=(1/6)*(2/6)
5) First dice: 5 ... Second dice: 6 ... P=(1/6)*(1/6)

The sum of probabilities of the 5 scenarios: 15/36

GMAT Club team member

Joined: 02 Sep 2009

Posts: 12081

Followers: 1876

Kudos [?]: 10077 [0], given: 955

Re: Please help (Probability w. dice) [#permalink]

07 Jun 2010, 08:33

test800 wrote:

When two dice are thrown, what is the probability that the score on the second dice is higher than the score on the first dice?

[Reveal] Spoiler:

5/12

Please explain

There are 6*6=36 possible outcomes when you throw 2 dice.

In 6 of these outcomes there will be a tie (1-1, 2-2, 3-3, ..., 6-6). 30 outcomes left: now in half of these outcomes (30/2=15) the score of die #1 will be more than the score of die #2 and in another half of the outcomes the score of die #1 will be less than the score of die #2. So P(#2>#1)=\frac{15}{36}=\frac{5}{12}.

Answer: \frac{5}{12}.

Hope it helps.
_________________

PLEASE READ AND FOLLOW: 11 Rules for Posting!!!

RESOURCES: [GMAT MATH BOOK]; 1. Triangles; 2. Polygons; 3. Coordinate Geometry; 4. Factorials; 5. Circles; 6. Number Theory; 7. Remainders; 8. Overlapping Sets; 9. PDF of Math Book; 10. Remainders

COLLECTION OF QUESTIONS:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. NEW!!! ,11 Mixed Questions NEW!!!, 12 Fresh Meat NEW!!!

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS ; 9 Devil's Dozen!!!; 10 Number Properties set. NEW!!!, 11 New DS set. NEW!!!

What are GMAT Club Tests?
25 extra-hard Quant Tests

Find out what's new at GMAT Club - latest features and updates

Re: Please help (Probability w. dice) [#permalink] 07 Jun 2010, 08:33

		Similar topics	Author	Replies	Last post
Similar Topics:		Probability - Dice -- Need Clarification	Praetorian	1	24 Aug 2003, 15:47
		Probability question--help please :)	slkp99	1	29 Sep 2003, 17:52
		Please help - probability question	Kerby	6	26 Nov 2006, 20:33
	5	Probability Question - Please help	konst75	8	30 Aug 2009, 01:09
		Pls help (Probability w. dice)	test800	3	07 Jun 2010, 06:46

Please help (Probability w. dice)

Main navigation

GMAT Resources

Partners

MBA Resources

GMAT ® is a registered trademark of the Graduate Management Admission Council ® (GMAC ®). GMAT Club's website has not been reviewed or endorsed by GMAC.

GMAT Courses

Admissions Consulting

Please help (Probability w. dice)

Please help (Probability w. dice)

Main navigation

GMAT Resources

Partners

MBA Resources