BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem
TTP OnDemand GMAT Video Course
Featured Course

Target Test Prep GMAT OnDemand

Scott Woodbury-Stewart’s private virtual classroom — 400 hours of master-class video lessons for the GMAT Focus Edition.

  • 715+ score guarantee — highest in the industry (99th percentile)
  • 52 chapters · 1,500+ lessons · 4,000+ practice questions
  • 400 hours of video · 1,500+ instructor-led HD smartboard lessons
  • 300,000+ students accepted to Harvard, Stanford, Wharton, Booth & Sloan & more
  • 24/7 live support + weekly Zoom office hours with GMAT instructors
  • TTP AI Assist — 24/7 AI-powered virtual tutor for instant help
  • 1,200+ flashcards + AI-powered study assistant & daily calendar
  • OnDemand, LiveTeach & GMAT Bootcamp formats available
  • Also: GRE, SAT Math & Executive Assessment courses
  • MBA Admissions Consulting now available
  • 🏆 2025 EdTech Breakthrough Award: Test Prep Solution Provider of the Year
  • 200,000+ students served
  • 5-day free trial — $0 to start, no auto-billing, cancel anytime
★★★★★ 5.0 (559 reviews)
130-pt guarantee
$0 to start then $127/mo
Start Free 5-Day Trial Read 559 Reviews →

cookies with SD

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
User avatar
Master | Next Rank: 500 Posts
Posts: 232
Joined: Fri Jun 18, 2010 7:09 amFollowed by: 2 members
Thanked: 1 times
by ruplun » Fri May 06, 2011 9:01 pm
Brett discovers that 150 bags of his favorite cookie contain a total of 3750 cookies.He then det
ermines that the cookies in a bag are normally distributed with a stndard deviation of 15.When Brett goes to the store to buy a bag of his favorite cookies, how many of the 1200 bags in the store contain more than 30 cookies?
A.24
B.25
C.50
D.192
E.600
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Legendary Member
Posts: 1112
Joined: Sat Feb 26, 2011 11:16 amFollowed by: 49 members
Thanked: 77 times

by atulmangal » Fri May 06, 2011 11:27 pm
ruplun wrote:Brett discovers that 150 bags of his favorite cookie contain a total of 3750 cookies.He then det
ermines that the cookies in a bag are normally distributed with a stndard deviation of 15.When Brett goes to the store to buy a bag of his favorite cookies, how many of the 1200 bags in the store contain more than 30 cookies?
A.24
B.25
C.50
D.192
E.600
This seems out of syllabus question...is this an official question???
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 232
Joined: Fri Jun 18, 2010 7:09 amFollowed by: 2 members
Thanked: 1 times

by ruplun » Fri May 06, 2011 11:55 pm
its a part of syllabus....mean and sd are there in gmat
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 amFollowed by: 3 members
Thanked: 85 times

by clock60 » Sat May 07, 2011 12:03 am
the mean number of cookies is 3750/150=25
and SD is 15. with prob 68,26% the number of cookies will fall in to the (25+15) and (25-15) i mean with in one SD
and at least 68,26/2=34% will contain more then 25 cookies.
0,34*1200=408.
only answer E makes sence here.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
User avatar
Master | Next Rank: 500 Posts
Posts: 232
Joined: Fri Jun 18, 2010 7:09 amFollowed by: 2 members
Thanked: 1 times

by ruplun » Sat May 07, 2011 12:53 am
Can't understand this explanation..please can anyone explain in detail
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Legendary Member
Posts: 1112
Joined: Sat Feb 26, 2011 11:16 amFollowed by: 49 members
Thanked: 77 times

by atulmangal » Sat May 07, 2011 6:24 am
ruplun wrote:Can't understand this explanation..please can anyone explain in detail
Thats what i actually wanna tell u..i know standard deviation and mean etc is a part of syllabus but this extra piece of info regrading Standard deviation needed to solve this question is out of syllabus...here is one link where @Stuart suggests the same..

https://www.beatthegmat.com/standard-dev ... t8560.html
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1