Author 
Message 
TAGS:

Hide Tags

Intern
Joined: 16 May 2017
Posts: 5

What is the probability that the sum of two dice will yield a 10 or lo
[#permalink]
Show Tags
Updated on: 11 Nov 2017, 01:22
Question Stats:
61% (00:45) correct 39% (00:57) wrong based on 113 sessions
HideShow timer Statistics
What is the probability that the sum of two dice will yield a 10 or lower? A. 34/36 B. 33/36 C. 32/36 D. 31/36 E. 30/36 Its the question from Manhattan GMAT Number Proporties page 65. Im not able to to understand ehy there are just three combination (5+6,6+5,6+6) and not 4 with the 6+6 again?? I´m such an idiot
Official Answer and Stats are available only to registered users. Register/ Login.
Originally posted by Henni on 10 Nov 2017, 16:00.
Last edited by Bunuel on 11 Nov 2017, 01:22, edited 1 time in total.
Renamed the topic and edited the question.





Magoosh GMAT Instructor
Joined: 28 Dec 2011
Posts: 4665

Re: What is the probability that the sum of two dice will yield a 10 or lo
[#permalink]
Show Tags
10 Nov 2017, 17:19
Henni wrote: Its the question from Manhattan GMAT Nzmber Proporties page 65. What is the probability that the sum of two dice will yield a 10 or lower? Im not able to to understand ehy there are just three combination (5+6,6+5,6+6) and not 4 with the 6+6 again?? I´m such an idiot Dear Henni, I'm happy to respond. My friend, think of physical dice. To make it easy to distinguish them, let's say we have one red die and one green die. What are the possibilities in which the sum is greater than 10? (1) red = 5, green = 6 (2) red = 6, green = 5 (3) red = 6, green = 6 There's only one way to get 12that's when both the red die and the green die show a 6. There's only one way for that to happen, whereas in the case of 11, there are two different things each die is doing to get those two results. Does this make sense? Mike
_________________
Mike McGarry Magoosh Test Prep
Education is not the filling of a pail, but the lighting of a fire. — William Butler Yeats (1865 – 1939)



Intern
Joined: 29 Dec 2016
Posts: 29
Location: India
Concentration: Finance
WE: Supply Chain Management (Energy and Utilities)

Re: What is the probability that the sum of two dice will yield a 10 or lo
[#permalink]
Show Tags
15 Jan 2018, 07:40
Dear all,
Just in case someone does not prefer to find the probability of the sum greater than 10, and then subtract the answer from 1 to get the probability of the sum a 10 or below, see below:
All possibilities of the sum a 10 or below:
Die 1 (value)  Die 2 (no of possibilities) 1  6 cases (1 to 6) 2  6 cases (1 to 6) 3  6 cases (1 to 6) 4  6 cases (1 to 6) 5  5 cases (1 to 6) 6  4 cases (1 to 6) Total = 33 cases
All possibilities for 2 dies = 6 x 6 = 36 cases
Probability of sum a 10 or below = 33/36
Regards, Louis



Retired Moderator
Joined: 28 May 2014
Posts: 528

Re: What is the probability that the sum of two dice will yield a 10 or lo
[#permalink]
Show Tags
15 Jan 2018, 08:11
Henni wrote: What is the probability that the sum of two dice will yield a 10 or lower? A. 34/36 B. 33/36 C. 32/36 D. 31/36 E. 30/36 Its the question from Manhattan GMAT Number Proporties page 65. Im not able to to understand ehy there are just three combination (5+6,6+5,6+6) and not 4 with the 6+6 again?? I´m such an idiot There are 3 possible combination for to get higher than 10 from two dices: D1  6 + D2 6 = 12 D1  6 + D2 5 = 11 D1  5 + D2 6 = 11 Now total combinations = 6*6 = 36 Remaining combinations = 36  3 = 33 Hence, probability to get 10 or lower = 33/36. Answer B.
_________________
440 to 730: If I Can, You Can Too



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 12176
Location: United States (CA)

Re: What is the probability that the sum of two dice will yield a 10 or lo
[#permalink]
Show Tags
17 Feb 2018, 14:43
Hi All, With this prompt, you might find it beneficial to 'write everything out'  while it would take a little bit of work, you would be able to physically see all of the possibilities, which would make dealing with the concept easier. Since we are rolling two 6sided dice, there are (6)(6) = 36 possible outcomes. Those outcomes are.... 11,12,13,14,15,16 21,22,23,24,25,26 31,32,33,34,35,36 41,42,43,44,45,46 51,52,53,54,55,56 61,62,63,64,65,66 Of these 36 outcomes you can either calculate what you WANT or what you DON'T WANT (and subtract that from the number 1). The second method is easier here... There are 3 options that DO NOT fit what you're looking for.... 3/36 = 1/12 1  1/12 = = 11/12 = the options that you ARE looking for. Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
760+: Learn What GMAT Assassins Do to Score at the Highest Levels Contact Rich at: Rich.C@empowergmat.com
Rich Cohen
CoFounder & GMAT Assassin
Special Offer: Save $75 + GMAT Club Tests Free
Official GMAT Exam Packs + 70 Pt. Improvement Guarantee www.empowergmat.com/
***********************Select EMPOWERgmat Courses now include ALL 6 Official GMAC CATs!***********************



Intern
Joined: 31 Jan 2018
Posts: 16

Re: What is the probability that the sum of two dice will yield a 10 or lo
[#permalink]
Show Tags
18 Feb 2018, 01:31
Try to first figure out is calculating the favorable probability easy or calculating the nonfavorable probability is easy.Here calculating the non favorable probability would be easy.So non favorable event would be getting a 11 or 12.
Probability of getting a 11 is Favorable outcomes/Total Outcomes=2/36. Probability of getting a 12 is 1/36 So required probability=1(1/36+2/36) =13/36=33/36 So answer is B




Re: What is the probability that the sum of two dice will yield a 10 or lo &nbs
[#permalink]
18 Feb 2018, 01:31






