Check GMAT Club Decision Tracker for the Latest School Decision Releases https://gmatclub.com/AppTrack

 It is currently 25 May 2017, 02:33

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# Given a spinner with four sections of equal size labeled

Author Message
TAGS:

### Hide Tags

Intern
Joined: 14 Nov 2011
Posts: 6
Followers: 0

Kudos [?]: 7 [0], given: 0

Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

01 May 2012, 03:28
4
This post was
BOOKMARKED
00:00

Difficulty:

15% (low)

Question Stats:

63% (01:39) correct 37% (00:31) wrong based on 219 sessions

### HideShow timer Statistics

Given a spinner with four sections of equal size labeled A, B, C, and D, what is the probability of NOT getting an A after spinning the spinner two times?

A. 15/16
B. 9/16
C. 1/2
D. 1/4
E. 1/8
[Reveal] Spoiler: OA
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728

Kudos [?]: 106080 [0], given: 11607

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

01 May 2012, 03:38
Expert's post
1
This post was
BOOKMARKED
Given a spinner with four sections of equal size labeled A, B, C, and D, what is the probability of NOT getting an A after spinning the spinner two times?

A. 15/16
B. 9/16
C. 1/2
D. 1/4
E. 1/8

The probability of NOT getting an A after spinning the spinner two times is 3/4*3/4=9/16 (so getting any of the remaining 3 letters out of 4).

_________________
Manager
Joined: 28 Sep 2011
Posts: 70
Location: United States
GMAT 1: 520 Q34 V27
GMAT 3: 690 Q47 V38
GPA: 3.01
WE: Information Technology (Commercial Banking)
Followers: 1

Kudos [?]: 31 [0], given: 10

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

01 May 2012, 10:31
Bunel, if you don't mind I want to expand on this problem for other probability concepts.

A. If I was to do 1 - (1/4*1/4) = 15/16.....This should be the right answer to what type of question?
C. 1/4 + 1/4 = 1/2, I assume this would be the right answer for "Probability of hitting A on any one of the two tries"?
Intern
Joined: 03 Apr 2012
Posts: 27
Followers: 0

Kudos [?]: 13 [0], given: 10

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

02 May 2012, 16:26
ashish8 wrote:
Bunel, if you don't mind I want to expand on this problem for other probability concepts.

A. If I was to do 1 - (1/4*1/4) = 15/16.....This should be the right answer to what type of question?
C. 1/4 + 1/4 = 1/2, I assume this would be the right answer for "Probability of hitting A on any one of the two tries"?

I am going to give it a shot, hopefully someone can confirm/correct me.
For A - that will be the right answer if the question were, what is the probablity if the hits atleast once if spun twice?
p(e) = 1 - (p(no A at all)

For B - that will be right, if the question were, what is the probality if spinner hit A on first spin or second spin?
Manager
Joined: 28 Sep 2011
Posts: 70
Location: United States
GMAT 1: 520 Q34 V27
GMAT 3: 690 Q47 V38
GPA: 3.01
WE: Information Technology (Commercial Banking)
Followers: 1

Kudos [?]: 31 [0], given: 10

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

02 May 2012, 16:34
Jay wouldn't the probability of A at least once be, 1 - Probability of NOT A = 1 - (3/4*3/4) = 1 - 9/16 = 7/16 ?
Math Expert
Joined: 02 Sep 2009
Posts: 38862
Followers: 7728

Kudos [?]: 106080 [1] , given: 11607

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

03 May 2012, 12:49
1
KUDOS
Expert's post
The probability of:
Getting A at leas once after spinning the spinner two times is 1-3/4*3/4=7/16;
Getting A only once after spinning the spinner two times is 1/4*3/4+3/4*1/4=6/16;
NOT getting A on both spins (so no AA) is 1-1/4*1/4=15/16.

Hope it's clear.
_________________
Manager
Joined: 07 Feb 2008
Posts: 63
Location: United States
WE: Consulting (Computer Software)
Followers: 3

Kudos [?]: 83 [0], given: 14

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

03 May 2012, 19:08
ashish8 wrote:
Bunel, if you don't mind I want to expand on this problem for other probability concepts.

A. If I was to do 1 - (1/4*1/4) = 15/16.....This should be the right answer to what type of question?
C. 1/4 + 1/4 = 1/2, I assume this would be the right answer for "Probability of hitting A on any one of the two tries"?

it should be (1 - 1/4) * (1 - 1/4),
not 1 - (1/4*1/4)

this is because both need to happen simultaneousluy, so we need to multiply. if both can happen idepedently, we can add.
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7373
Location: Pune, India
Followers: 2287

Kudos [?]: 15103 [0], given: 224

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

04 May 2012, 20:55
ashish8 wrote:
C. 1/4 + 1/4 = 1/2, I assume this would be the right answer for "Probability of hitting A on any one of the two tries"?

The right answer is (1/4) + (1/4) - (1/4)*(1/4) = 7/16
and the right question is: What is the probability that you get A at least once? or What is the probability of getting A on any one of the two tries or on both?

You subtract the probability of getting A on both spins because you have double counted it. Think SETS. The first (1/4) includes the probability of 'A on both spins'. The second (1/4) also includes the probability of 'A on both spins'. So you need to subtract it once.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for $199 Veritas Prep Reviews GMAT Club Legend Joined: 09 Sep 2013 Posts: 15434 Followers: 649 Kudos [?]: 208 [0], given: 0 Re: Given a spinner with four sections of equal size labeled [#permalink] ### Show Tags 01 Dec 2013, 06:28 Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email. _________________ Current Student Status: Everyone is a leader. Just stop listening to others. Joined: 22 Mar 2013 Posts: 960 Location: India GPA: 3.51 WE: Information Technology (Computer Software) Followers: 171 Kudos [?]: 1611 [0], given: 229 Re: Given a spinner with four sections of equal size labeled [#permalink] ### Show Tags 17 May 2014, 13:07 Meaning is confusing ... after spinning 2 times .. means third time or more.. or spinning spinner by hand 2 times.. _________________ Piyush K ----------------------- Our greatest weakness lies in giving up. The most certain way to succeed is to try just one more time. ― Thomas A. Edison Don't forget to press--> Kudos My Articles: 1. WOULD: when to use? | 2. All GMATPrep RCs (New) Tip: Before exam a week earlier don't forget to exhaust all gmatprep problems specially for "sentence correction". Veritas Prep GMAT Instructor Joined: 16 Oct 2010 Posts: 7373 Location: Pune, India Followers: 2287 Kudos [?]: 15103 [0], given: 224 Re: Given a spinner with four sections of equal size labeled [#permalink] ### Show Tags 18 May 2014, 21:36 PiyushK wrote: Meaning is confusing ... after spinning 2 times .. means third time or more.. or spinning spinner by hand 2 times.. "Not getting A after spinning 2 times" means not getting A in either of the two spins. _________________ Karishma Veritas Prep | GMAT Instructor My Blog Get started with Veritas Prep GMAT On Demand for$199

Veritas Prep Reviews

Manager
Joined: 30 Dec 2015
Posts: 90
GPA: 3.92
WE: Engineering (Aerospace and Defense)
Followers: 0

Kudos [?]: 10 [0], given: 153

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

24 Oct 2016, 20:22
Bunuel wrote:
The probability of:
Getting A at leas once after spinning the spinner two times is 1-3/4*3/4=7/16;
Getting A only once after spinning the spinner two times is 1/4*3/4+3/4*1/4=6/16;
NOT getting A on both spins (so no AA) is 1-1/4*1/4=15/16.

Hope it's clear.

Hey Bunuel,

what is the difference between "NOT getting an A after spinning the spinner two times" and "NOT getting A on both spins"?
_________________

If you analyze enough data, you can predict the future.....its calculating probability, nothing more!

Intern
Joined: 26 Aug 2016
Posts: 10
Followers: 0

Kudos [?]: 7 [0], given: 29

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

04 Jan 2017, 07:35
Hey guys! Don't quite understand the logic on Bunuels post:

Getting A only once after spinning the spinner two times is 1/4*3/4+3/4*1/4=6/16;
Manager
Joined: 30 Dec 2015
Posts: 90
GPA: 3.92
WE: Engineering (Aerospace and Defense)
Followers: 0

Kudos [?]: 10 [0], given: 153

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

19 Feb 2017, 20:45
iqahmed83 wrote:
Hey guys! Don't quite understand the logic on Bunuels post:

Getting A only once after spinning the spinner two times is 1/4*3/4+3/4*1/4=6/16;

Either get {"A" in the first spin and "non A" in the second spin} OR get {"non A" in the first spin and "A" in the second spin}

Hence:
{(P of A) & (P of non A)} or {(P of non A) & (P of A)}
_________________

If you analyze enough data, you can predict the future.....its calculating probability, nothing more!

Senior Manager
Joined: 24 Oct 2016
Posts: 298
Followers: 1

Kudos [?]: 12 [0], given: 84

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

10 Mar 2017, 22:45
akrish1982 wrote:
ashish8 wrote:
Bunel, if you don't mind I want to expand on this problem for other probability concepts.

A. If I was to do 1 - (1/4*1/4) = 15/16.....This should be the right answer to what type of question?
C. 1/4 + 1/4 = 1/2, I assume this would be the right answer for "Probability of hitting A on any one of the two tries"?

it should be (1 - 1/4) * (1 - 1/4),
not 1 - (1/4*1/4)

this is because both need to happen simultaneousluy, so we need to multiply. if both can happen idepedently, we can add.

hii ,
karishma , can you guide me where am i wrong in these solutions ...
1 p(A or B) = 1/4+1/4-1/4*1/4= 7/16 now we can calculate not getting A that will be 1-7/16=9/16 as it is the answer
2. to me why is this wrong this method 1-1/4*1/4=15/16 for the above problem just because we are asked to calculate the probability of not getting A on both the tires,that's why and this solution will work if we are asked to calculate at least one . let me know if i am missing anything.../

thanks
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7373
Location: Pune, India
Followers: 2287

Kudos [?]: 15103 [2] , given: 224

Re: Given a spinner with four sections of equal size labeled [#permalink]

### Show Tags

11 Mar 2017, 01:48
2
KUDOS
Expert's post
1
This post was
BOOKMARKED
nks2611 wrote:
akrish1982 wrote:
ashish8 wrote:
Bunel, if you don't mind I want to expand on this problem for other probability concepts.

A. If I was to do 1 - (1/4*1/4) = 15/16.....This should be the right answer to what type of question?
C. 1/4 + 1/4 = 1/2, I assume this would be the right answer for "Probability of hitting A on any one of the two tries"?

it should be (1 - 1/4) * (1 - 1/4),
not 1 - (1/4*1/4)

this is because both need to happen simultaneousluy, so we need to multiply. if both can happen idepedently, we can add.

hii ,
karishma , can you guide me where am i wrong in these solutions ...
1 p(A or B) = 1/4+1/4-1/4*1/4= 7/16 now we can calculate not getting A that will be 1-7/16=9/16 as it is the answer
2. to me why is this wrong this method 1-1/4*1/4=15/16 for the above problem just because we are asked to calculate the probability of not getting A on both the tires,that's why and this solution will work if we are asked to calculate at least one . let me know if i am missing anything.../

thanks

If you are talking about the result after spinning two times, the probability will be multiplied. You spin once, AND you spin again. So it is not P(A or B). It is P(A and B)

1/4 is the probability of getting A on a spin.

(1/4)*(1/4) is the probability that you will get A on BOTH spins.

Hence, 1 - (1/4)(1/4) = 15/16 is the probability the you will not get A on both spins. You could get A on one spin though.
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

Re: Given a spinner with four sections of equal size labeled   [#permalink] 11 Mar 2017, 01:48
Similar topics Replies Last post
Similar
Topics:
1 To create a part for a certain piece of machinery, four equal-size wed 3 15 May 2017, 17:33
4 The size of a flat-screen television is given as the length of the 8 30 Jul 2016, 07:31
11 A pyramid with four equal-sized flat surfaces and a base of 10 14 Nov 2016, 01:20
3 The size of a television screen is given as the length of 4 12 Dec 2013, 12:43
4 The size of a television screen is given as the length of 7 31 Jul 2015, 00:17
Display posts from previous: Sort by

# Given a spinner with four sections of equal size labeled

 Powered by phpBB © phpBB Group and phpBB SEO Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.