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

It is currently 24 Jun 2018, 17:31
Search
Register
GMAT Club Tests
Decision Tracker
My Rewards
New posts
Unanswered

Close

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
Your Progress

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

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Go to My Error Log Learn more
Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar
CLICK HERE TO HIDE/SHOW EVENTS

At 3 pm, Jennifer went into labor. There is a 70% chance her baby will

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
  Sort by Date Sort by Kudos  
Search for:
 
Print view
First unread post
Author Message
TAGS:

Hide Tags
Expert Post
Math Expert
User avatar
V
Joined: 02 Sep 2009
Posts: 46319
Premium Member CAT Tests
Top Member of the Month
At 3 pm, Jennifer went into labor. There is a 70% chance her baby will [#permalink]

Show Tags

New post 29 Jan 2018, 05:41
2
00:00
A
B
C
D
E

Difficulty:

  45% (medium)

Question Stats:

57% (01:10) correct 43% (00:52) wrong based on 60 sessions

HideShow timer Statistics

At 3 pm, Jennifer went into labor. There is a 70% chance her baby will be born each hour that she is in labor. What is the probability that her baby will be born at 6 pm on the same day?

(A) 0.027
(B) 0.063
(C) 0.147
(D) 0.27
(E) 0.343
Spoiler: OA

_________________

New to the Math Forum?
Please read this: Ultimate GMAT Quantitative Megathread | All You Need for Quant | PLEASE READ AND FOLLOW: 12 Rules for Posting!!!

Resources:
GMAT Math Book | Triangles | Polygons | Coordinate Geometry | Factorials | Circles | Number Theory | Remainders; 8. Overlapping Sets | PDF of Math Book; 10. Remainders | GMAT Prep Software Analysis | SEVEN SAMURAI OF 2012 (BEST DISCUSSIONS) | Tricky questions from previous years.

Collection of Questions:
PS: 1. Tough and Tricky questions; 2. Hard questions; 3. Hard questions part 2; 4. Standard deviation; 5. Tough Problem Solving Questions With Solutions; 6. Probability and Combinations Questions With Solutions; 7 Tough and tricky exponents and roots questions; 8 12 Easy Pieces (or not?); 9 Bakers' Dozen; 10 Algebra set. ,11 Mixed Questions, 12 Fresh Meat

DS: 1. DS tough questions; 2. DS tough questions part 2; 3. DS tough questions part 3; 4. DS Standard deviation; 5. Inequalities; 6. 700+ GMAT Data Sufficiency Questions With Explanations; 7 Tough and tricky exponents and roots questions; 8 The Discreet Charm of the DS; 9 Devil's Dozen!!!; 10 Number Properties set., 11 New DS set.


What are GMAT Club Tests?
Extra-hard Quant Tests with Brilliant Analytics

BSchool Forum Moderator
User avatar
V
Joined: 26 Feb 2016
Posts: 2841
Location: India
GPA: 3.12
Premium Member
Re: At 3 pm, Jennifer went into labor. There is a 70% chance her baby will [#permalink]

Show Tags

New post 29 Jan 2018, 06:17
Bunuel wrote:
At 3 pm, Jennifer went into labor. There is a 70% chance her baby will be born each hour that she is in labor. What is the probability that her baby will be born at 6 pm on the same day?

(A) 0.027
(B) 0.063
(C) 0.147
(D) 0.27
(E) 0.343


If the probability that the baby is born in an hour is 0.7(70%),
then the probability that the baby is not born in that hour is 0.3

If the baby is to born at 6, the baby can't be born at 4 or 5,
but must definitely be born at 6.
The probability that the baby is born at 6 is \(0.3*0.3*0.7 =\) 0.063(Option B)
_________________

You've got what it takes, but it will take everything you've got

Manager
Manager
avatar
B
Joined: 24 Jun 2013
Posts: 85
GMAT ToolKit User
Re: At 3 pm, Jennifer went into labor. There is a 70% chance her baby will [#permalink]

Show Tags

New post 29 Jan 2018, 07:24
P(Born)= 0.7; P(not born)= 0.3
for the baby to be born at 6 pm, we have
P(not born 4 pm) * P(not born 5 pm) * P(born 6 pm) = 0.3*0.3*0.7 = 0.063
_________________

If this post helped you learn something pls give kudos

Expert Post
Target Test Prep Representative
User avatar
G
Status: Head GMAT Instructor
Affiliations: Target Test Prep
Joined: 04 Mar 2011
Posts: 2570
Re: At 3 pm, Jennifer went into labor. There is a 70% chance her baby will [#permalink]

Show Tags

New post 30 Jan 2018, 11:18
Bunuel wrote:
At 3 pm, Jennifer went into labor. There is a 70% chance her baby will be born each hour that she is in labor. What is the probability that her baby will be born at 6 pm on the same day?

(A) 0.027
(B) 0.063
(C) 0.147
(D) 0.27
(E) 0.343


For the baby to be born at 6 pm, the baby can not be born at 4 pm nor at 5 pm. Note that since the probability that the baby is born at each hour is 0.7, the probability that the baby is not born in that hour is 1 - 0.7 = 0.3. Thus, the probability that the baby is born at 6pm is (0.3) x (0.3) x (0.7) = 0.063.

Answer: B
_________________

Jeffery Miller
Head of GMAT Instruction

GMAT Quant Self-Study Course
500+ lessons 3000+ practice problems 800+ HD solutions

Expert Post
e-GMAT Representative
User avatar
G
Joined: 04 Jan 2015
Posts: 1571
Re: At 3 pm, Jennifer went into labor. There is a 70% chance her baby will [#permalink]

Show Tags

New post 31 Jan 2018, 05:18
Bunuel wrote:
At 3 pm, Jennifer went into labor. There is a 70% chance her baby will be born each hour that she is in labor. What is the probability that her baby will be born at 6 pm on the same day?

(A) 0.027
(B) 0.063
(C) 0.147
(D) 0.27
(E) 0.343



    • If we want to find the probability that the baby is born at 6pm, we need to consider that fact that the baby could not have been born in the hours 3pm to 4pm, 4pm to 5pm.
    • If the probability of having the baby in an hour = 0.7
      o The probability of not have the baby within that hour = 1 – 0.7 = 0.3
      o Thus, the probability that baby is not born after 3pm and till 4pm = 0.3
      o The probability that baby is not born after 4pm and till 5pm = 0.3
    • The probability that baby is born between after 5pm and at 6pm = 0.7
    • Thus, the overall probability of having the baby at 6pm when the labor starts at 3PM = 0.3 * 0.3 * 0.7 = 0.063

Correct answer: Option B

Regards,
Saquib
Quant Expert
e-GMAT
_________________












| '4 out of Top 5' Instructors on gmatclub | 70 point improvement guarantee | www.e-gmat.com
Re: At 3 pm, Jennifer went into labor. There is a 70% chance her baby will   [#permalink] 31 Jan 2018, 05:18
Print view
First unread post
Display posts from previous: Sort by

At 3 pm, Jennifer went into labor. There is a 70% chance her baby will

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  

Moderators: chetan2u, VeritasPrepKarishma, niks18, mikemcgarry, Bunuel, generis

Search for:


GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

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®.

Main navigation

GMAT Resources

Partners

MBA Resources

www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions