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.
May 2101:00 AM EDT
-02:00 AM EDT
Looking for your GMAT motivation to break through the score plateau? Pragati improved her score by massive 160 points with strategic guidance and hard-work! Find out how personalized mentorship and a strong mindset can turn GMAT struggles into success.
May 2012:30 AM EDT
-01:30 AM EDT
Struggling to find the right strategies to score a 99 %ile on GMAT Focus? Riya (GMAT 715) boosted her score by 100-points in just 15 days! Discover how the right mentorship, tailored strategies, and an unwavering mindset can transform your GMAT prep.
May 2008:00 AM PDT
-08:30 AM PDT
What’s in it for you- Live Profile Evaluation Chat Session with Jenifer Turtschanow, CEO, ARINGO. Come with your details prepared and ARINGO will share insights! Pre-MBA Role/Industry, YOE, Exam Score, C/GPA, ECs Post-MBA Role/ Industry & School List.
May 2310:00 AM PDT
-11:00 AM PDT
Video explanations + diagnosis of 10 weakest areas + 150+ short videos + study plan!
Jun 1006:00 AM PDT
-06:15 PM PDT
Register for the GMAT Club Virtual MBA Spotlight Fair – the world’s premier event for serious MBA candidates. This is your chance to hear directly from Admissions Directors at nearly every Top 30 MBA program..
15 Dec 2025, 09:00
Kudos
Bookmarks
At least one: 0.9
p: 0.5
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
65%
(hard)
Question Stats:
70% (02:12) correct
30%
(02:17)
wrong
based on 355
sessions
History
Date
Time
Result
Not Attempted Yet
12 Days of Christmas Competition
This question is part of our holiday event
Win $40,000 in prizes: courses, tests, and more
John has a 0.8 probability of eating breakfast with bacon and eggs, and Mary has a probability p of doing yoga in the morning.
If these events are independent, select for At least one the probability that at least one of these events occurs, and select for p the probability of Mary doing yoga in the morning that would be jointly consistent with the given information. Make only two selections, one in each column.
| At least one | p | |
| 0.2 | ||
| 0.4 | ||
| 0.5 | ||
| 0.85 | ||
| 0.9 | ||
| 0.95 |
ShowHide Answer
Official Answer
At least one: 0.9
p: 0.5
I31-16
15 Dec 2025, 10:00
Kudos
Bookmarks
John has a 0.8 probability of eating breakfast with bacon and eggs, and Mary has a probability p of doing yoga in the morning.
If these events are independent, select for At least one the probability that at least one of these events occurs, and select for p the probability of Mary doing yoga in the morning that would be jointly consistent with the given information. Make only two selections, one in each column.
Since the events are independent, P(at least one) = P(breakfast) + P(yoga) - P(both). So, we get:
P(at least one) = P(breakfast) + P(yoga) - P(both) =
= 0.8 + p - P(breakfast) * P(yoga) =
= 0.8 + p - 0.8 * p =
= 0.8 + 0.2p
Obviously, P(at least one) must be greater than 0.8, so 0.85, 0.9, or 0.95.
Substituting 0.85 gives p = 0.25, which is absent from the options.
Substituting 0.9 gives p = 0.5, which is present in the options.
Therefore, the correct answer is p = 0.5, and the probability of at least one event occurring is 0.9.
GMAT-Club-Forum-yxtg1vxl.png [ 11.53 KiB | Viewed 2218 times ]
If these events are independent, select for At least one the probability that at least one of these events occurs, and select for p the probability of Mary doing yoga in the morning that would be jointly consistent with the given information. Make only two selections, one in each column.
Since the events are independent, P(at least one) = P(breakfast) + P(yoga) - P(both). So, we get:
P(at least one) = P(breakfast) + P(yoga) - P(both) =
= 0.8 + p - P(breakfast) * P(yoga) =
= 0.8 + p - 0.8 * p =
= 0.8 + 0.2p
Obviously, P(at least one) must be greater than 0.8, so 0.85, 0.9, or 0.95.
Substituting 0.85 gives p = 0.25, which is absent from the options.
Substituting 0.9 gives p = 0.5, which is present in the options.
Therefore, the correct answer is p = 0.5, and the probability of at least one event occurring is 0.9.
Attachment:
GMAT-Club-Forum-yxtg1vxl.png [ 11.53 KiB | Viewed 2218 times ]
General Discussion
15 Dec 2025, 09:40
Kudos
Bookmarks
probabilty for atleast 1 of them happening is
1 - p(none of both)
1 - 0.2(1-p)
for p = 0.5 we get above as 0.9
hence answer is 0.9, 0.5
1 - p(none of both)
1 - 0.2(1-p)
for p = 0.5 we get above as 0.9
hence answer is 0.9, 0.5
