Events & Promotions
|
|
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.
Customized
for You
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
22 Aug 2020, 08:23
Kudos
Bookmarks
D
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
95%
(hard)
Question Stats:
21% (02:19) correct
79%
(01:36)
wrong
based on 77
sessions
History
Date
Time
Result
Not Attempted Yet
Pam and Suzie each rolls a dice twice. What is the probability of them rolling the same set of numbers?
A. \(\frac{10}{216}\)
B. \(\frac{1}{36}\)
C. \(\frac{1}{18}\)
D. \(\frac{11}{216}\)
E. \(\frac{1}{6}\)
A. \(\frac{10}{216}\)
B. \(\frac{1}{36}\)
C. \(\frac{1}{18}\)
D. \(\frac{11}{216}\)
E. \(\frac{1}{6}\)
22 Aug 2020, 09:20
Kudos
Bookmarks
Rolling a pair and rolling distant no will give different probability.
Required Probability = 1/6 * 1/36 + 5/6 * 2/36
= 11/216
Required Probability = 1/6 * 1/36 + 5/6 * 2/36
= 11/216
22 Aug 2020, 10:04
Kudos
Bookmarks
We must separate the calcularions depending on whether the roll is a pair or not.
CASE 1: Pam rolls a pair
The probability of Pam rolling any pair {(1,1),(2,2)...,(6,6)} is 6/36. The probaility that Suzie rolls that exact pair is 1/36. Therefore, the probaility of both rolling the same pair is
6/36 * 1/36
= 1/6 * 1/36
= 1/216
Case 2: Pam does not roll a pair
The probaility of Pam rolling something different than a pair is 30/36. The probability of Suzie rolling that exact comination combination has a trick because there are 2 ways for her to roll the same numbers. For example if Pam rolls (2,3) then does not make any difference if Suzie rolls (2,3) or (3,2) the numbers are the same. So she has a probability of 2/36 to roll what Pam rolled.
Therefore the probability of both of them rolling the same non pair numbers is
30/36 * 2/36
= 5/6 * 2/36
= 10/216
Adding both cases we get that the total probaility is:
1/216 + 10/216 = 11/216
Hope it helps.
CASE 1: Pam rolls a pair
The probability of Pam rolling any pair {(1,1),(2,2)...,(6,6)} is 6/36. The probaility that Suzie rolls that exact pair is 1/36. Therefore, the probaility of both rolling the same pair is
6/36 * 1/36
= 1/6 * 1/36
= 1/216
Case 2: Pam does not roll a pair
The probaility of Pam rolling something different than a pair is 30/36. The probability of Suzie rolling that exact comination combination has a trick because there are 2 ways for her to roll the same numbers. For example if Pam rolls (2,3) then does not make any difference if Suzie rolls (2,3) or (3,2) the numbers are the same. So she has a probability of 2/36 to roll what Pam rolled.
Therefore the probability of both of them rolling the same non pair numbers is
30/36 * 2/36
= 5/6 * 2/36
= 10/216
Adding both cases we get that the total probaility is:
1/216 + 10/216 = 11/216
Hope it helps.
