Live GMAT classes with Target Test Prep start Nov 21 and Nov 22. First class free.

See classes
Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

Newsweek Readers’ Choice Awards 2026 winner: Target Test Prep, #1 Test Prep

Target Test Prep was voted #1 Best Test Prep in the 2026 Newsweek Readers’ Choice™ Awards.

★★★★★5.0563 reviews
GMATLiveTeachStarts Nov 22
Josh Braslow, Target Test Prep GMAT expert
LIVE ONLINE CLASSES

Get Ready for GMAT Test Day Faster with Live Online Classes

with Josh Braslow, 20+ years in test prep

Nov 22 · Josh Braslow
Sun · 9:30 AM to 12:30 PM ET
Included
40 hours of live online classes + 6 months of TTP OnDemand
  • Attend the first class for free
  • Every class is recorded, so you never fall behind
View classes & enroll
Limited seats availableTarget Test Prep
EALiveTeachOnDemandStart anytime
EXECUTIVE ASSESSMENT

Target Test Prep EA OnDemand

Self-paced EA prep. Study on your schedule.

EXECUTIVE ASSESSMENT

with

165+ EA score guarantee
$05-day trial no automatic billing
Schedule
Included
40 hours of live online classes plus six months of access to the complete TTP EA OnDemand course.
  • 165+ EA Score Guarantee
  • 4,100+ Quant, Verbal, and Integrated Reasoning practice questions
  • 400+ hours of in-depth video lessons
  • 3,000+ step-by-step video solutions
View EA class & enroll Start free 5-day trial
Limited cohort · enrollment openTrial includes full course accessTarget Test Prep
GMATOnDemandStart anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

715+ score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 563 reviewsTarget Test Prep

Geometry cylinder problem

Problem Solving — algebra and arithmetic
Expert replies
Post new topic Post Reply
Subscribe topic
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 4
Joined: Mon Jan 18, 2016 9:27 pm
by Emeka N. » Sun Apr 24, 2016 12:36 pm
How should I be thinking about problems like this one?
You do not have the required permissions to view the files attached to this post.
Top
Join the discussion
Source: — Quantitative Reasoning |
Senior | Next Rank: 100 Posts
Posts: 46
Joined: Sun Dec 27, 2015 7:03 amFollowed by: 1 member
Thanked: 8 times

by chetan.sharma » Mon Apr 25, 2016 4:58 am
Emeka N. wrote:How should I be thinking about problems like this one?
Hi,
we can see that the belt covers half the circumference of left wheel and half the circumference of right belt..
so it overall covers the entire circumference, which is 1*pi..
so the rest of the belt =15-pi..
this belt covers two times the distance between the centre of the wheels..
so our answer = (15-pi)/2
A
Top
Join the discussion

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 2095
Joined: Tue Dec 04, 2012 3:22 pmFollowed by: 247 members
Thanked: 1443 times

by ceilidh.erickson » Mon Apr 25, 2016 8:45 am
Here's an image to help clarify Chetan's point:

Image

The distance between the two centers is the same as the distance from the top of one circle to the top of the other. In other words, half of the non-circular part of the belt.

We can think of the belt as 2 curves (half-circles) + 2 straight lines:

Image

The two half-circles together would have the same circumference as a full circle: 1Ï€

Thus, the two straight lines would be the total of 15 minus the two half circles: 15 - π

One of those straight lines would thus be (15 - π)/2
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
Top
Join the discussion