GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 14 Oct 2019, 13:52

### 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

we will pick new questions that match your level based on your Timer History

Track

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

# What is the probability that a certain event A will not occur?

Author Message
TAGS:

### Hide Tags

Retired Moderator
Joined: 27 Oct 2017
Posts: 1256
Location: India
GPA: 3.64
WE: Business Development (Energy and Utilities)
What is the probability that a certain event A will not occur?  [#permalink]

### Show Tags

15 Dec 2018, 10:22
2
1
00:00

Difficulty:

15% (low)

Question Stats:

86% (00:42) correct 14% (00:33) wrong based on 54 sessions

### HideShow timer Statistics

GMATbuster's Weekly Quant Quiz#13 Ques #7

What is the probability that a certain event A will not occur?
1) The probability that event A will occur is thrice the probability that event A will not occur.
2) The probability that event A will occur is 0.75

_________________
Intern
Joined: 15 Nov 2018
Posts: 32
Location: United States
Concentration: Operations, Finance
GMAT 1: 650 Q48 V31
GPA: 3
WE: Engineering (Other)
Re: What is the probability that a certain event A will not occur?  [#permalink]

### Show Tags

15 Dec 2018, 10:37
Total probability = 1= 4x
X be the probability of not occuring
3x will be the probability to occur
So x= 1/4 ( probability to not occur)

2) probablity to occur is 0.75
To not occur will be 1-0.75 = 0.25

Ans= D.

Posted from my mobile device
GMAT Club Legend
Joined: 18 Aug 2017
Posts: 4987
Location: India
Concentration: Sustainability, Marketing
GPA: 4
WE: Marketing (Energy and Utilities)
Re: What is the probability that a certain event A will not occur?  [#permalink]

### Show Tags

16 Dec 2018, 02:04
1
PA+PnA=1
Pa=1-Pna
from 1:
The probability that event A will occur is thrice the probability that event A will not occur.
Pa=3Pna

1-Pna=3Pna
1=4Pna
Pna = .25
sufficient
from 2
The probability that event A will occur is 0.75

since Pa+Pna =1
Pna=1-.75 = .25

IMO D ..

Both sufficient
What is the probability that a certain event A will not occur?
1) The probability that event A will occur is thrice the probability that event A will not occur.
2) The probability that event A will occur is 0.75
_________________
If you liked my solution then please give Kudos. Kudos encourage active discussions.
Director
Joined: 13 Mar 2017
Posts: 728
Location: India
Concentration: General Management, Entrepreneurship
GPA: 3.8
WE: Engineering (Energy and Utilities)
Re: What is the probability that a certain event A will not occur?  [#permalink]

### Show Tags

16 Dec 2018, 09:59
DI Question : What is the probability that a certain event A will not occur?
P(A) = ?

Statement 1) : The probability that event A will occur is thrice the probability that event A will not occur.
P(A) = 3*P(A)
P(A) + P(A) = 1
3*P(A) + P(A) = 1
P(A) = 0.25
SUFFICIENT

2) The probability that event A will occur is 0.75
P(A) = 0.75
P(A) + P(A) = 1
P(A) = 0.25
SUFFICIENT

_________________
CAT 2017 (98.95) & 2018 (98.91) : 99th percentiler
UPSC Aspirants : Get my app UPSC Important News Reader from Play store.

MBA Social Network : WebMaggu

Appreciate by Clicking +1 Kudos ( Lets be more generous friends.)

What I believe is : "Nothing is Impossible, Even Impossible says I'm Possible" : "Stay Hungry, Stay Foolish".
Manager
Joined: 09 Jul 2018
Posts: 63
Re: What is the probability that a certain event A will not occur?  [#permalink]

### Show Tags

16 Dec 2018, 22:54
Probability of A occurring + Probability of A not occurring =1

P(A)+ P(A') = 1

Statement 1 gives that P(A)=3P(A')
hence P(A') can be calculated - sufficient

Statement 2 gives P(A) = 0.75
which gives P(A') = 0.25 - sufficient

Ans is D
Manager
Joined: 12 Apr 2017
Posts: 139
Location: United States
Concentration: Finance, Operations
GPA: 3.1
What is the probability that a certain event A will not occur?  [#permalink]

### Show Tags

17 Dec 2018, 13:22
P(occurring, not occurring) = 1
Q: not occurring?

1) Not occurring = x, occurring 3 times x
3x +x = 1
4x = 1
x = 1/4

Probability of not occurring equals 1/4

2) occurs is .75

1- P(occurs) = not occuring

1 - 0.75 = 0.25

sufficient

Both are sufficient = D
What is the probability that a certain event A will not occur?   [#permalink] 17 Dec 2018, 13:22
Display posts from previous: Sort by