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 →

Quantitative Review DS 58)

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 236
Joined: Fri Nov 28, 2008 9:16 am
Thanked: 9 times
by El Cucu » Wed Feb 18, 2009 9:20 am
Hi Guys need an explanation regarding the total distance and the radii of the wheel.

58. What is the number of 360 degree rotations that a bicycle wheel made while rolling 100 meters in a straight line without slipping?

1) The diameter of the bicycle wheel, including the tire, was 0,5 meter.

2) The wheel made twenty 360 degree rotations per minute.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 35
Joined: Thu Nov 13, 2008 8:05 am
Thanked: 6 times

by shulapa » Wed Feb 18, 2009 9:28 am
Hi,

In order to know the number of rotation the wheel has done while passing through 100m we need to know the circumference of the wheel. The we can use this equation:
Distance/perimeter = number of rotation

(1) provides us with the wheel diameter so perimeter can be found via:

P=2pi*r=pi*d

Thus, sufficient.

(2) We are given the rotation speed of the wheel but we don't have any thing to connect speed to the distance (like time to pass the entire path).

Thus, insufficient

Therefore, A
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 236
Joined: Fri Nov 28, 2008 9:16 am
Thanked: 9 times

by El Cucu » Wed Feb 18, 2009 9:32 am
Still can't imagine why having the circumference we are able to answer the problem.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Junior | Next Rank: 30 Posts
Posts: 27
Joined: Sat Dec 29, 2007 1:37 amFollowed by: 1 member
Thanked: 2 times

by tini » Wed Feb 18, 2009 9:42 am
that's because when a wheel rolls once it covers a distance equal to the length of its circumference.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1