Events & Promotions
|
|
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
Track
Your Progress
Practice
Pays
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Apr 2601:30 AM EDT
-02:30 AM EDT
Learn how Keshav, a Chartered Accountant, scored an impressive 705 on GMAT in just 30 days with GMATWhiz's expert guidance. In this video, he shares preparation tips and strategies that worked for him, including the mock, time management, and more.
Apr 2512:30 AM EDT
-01:30 AM EDT
At one point, she believed GMAT wasn’t for her. After scoring 595, self-doubt crept in and she questioned her potential. But instead of quitting, she made the right strategic changes. The result? A remarkable comeback to 695. Check out how Saakshi did it.
Apr 2610:00 AM EDT
-11:00 AM EDT
The Target Test Prep course represents a quantum leap forward in GMAT preparation, a radical reinterpretation of the way that students should study. Try before you buy with a 5-day, full-access trial of the course for FREE!
Apr 2711:00 AM EDT
-12:00 PM EDT
Prefer video-based learning? The Target Test Prep OnDemand course is a one-of-a-kind video masterclass featuring 400 hours of lecture-style teaching by Scott Woodbury-Stewart, founder of Target Test Prep and one of the most accomplished GMAT instructors
Apr 2808:00 AM PDT
-11:00 AM PDT
Whether you are just beginning your MBA journey or fine-tuning your path to a 700+ score, GMAT Day is designed to give you a competitive edge.
May 0111:00 AM PDT
-12:00 PM PDT
Free- full-length test + 15 concept videos + 150+ short videos + study plan!
25 Apr 2017, 20:51
Kudos
Bookmarks
C
Be sure to select an answer first to save it in the Error Log before revealing the correct answer (OA)!
Difficulty:
25%
(medium)
Question Stats:
79% (02:08) correct
21%
(02:25)
wrong
based on 242
sessions
History
Date
Time
Result
Not Attempted Yet
Johan rides his bicycle to and from college everyday, and the round trip takes 2 hours. If the radius of the front wheel is 30 cm and the wheel makes 30000 rotations over the course of round trip, then which of the following is closest to Johan's average speed?
(A) 2π km/hr
(B) 4π km/hr
(C) 9π km/hr
(D) 10π km/hr
(E) 12π km/hr
(A) 2π km/hr
(B) 4π km/hr
(C) 9π km/hr
(D) 10π km/hr
(E) 12π km/hr
29 Apr 2017, 09:04
Kudos
Bookmarks
saswata4s
The total distance of the round trip is equal to the circumference of the wheel times the number of rotations over the course of the round trip. Since the radius of the wheel is 30 cm, the circumference is C = 2πr = 2 x π x 30 = 60π cm. Since the wheel makes 30,000 rotations over the course of the round trip, the total distance of the round trip is 60π x 30,000 = 1,800,000π cm. Since the round trip takes 2 hours and rate = distance/time, the rate is 1,800,000π/2 = 900,000π cm/hr.
Now we need to convert cm to km. Since 1 m = 100 cm, 900,000π cm = 9,000π m. Since 1 km = 1,000 m, 9,000π m = 9π km. Thus, the rate is 9π km/hr.
Answer: C
General Discussion
25 Apr 2017, 22:01
Kudos
Bookmarks
Radius of the wheel in KM = 30/100000 = 3/10000
Total distance travelled in the to and fro journey = total number of rotations * circumference of the wheel
= 30000 * 2 * π * 3/10000
= 3 * 2 * π * 3 = 18π
Johan's average speed = Total distance travelled in the to and fro journey/Total time taken in the to and fro journey
= 18π / 2 = 9π km/hr
Answer is (C) 9π km/hr
Total distance travelled in the to and fro journey = total number of rotations * circumference of the wheel
= 30000 * 2 * π * 3/10000
= 3 * 2 * π * 3 = 18π
Johan's average speed = Total distance travelled in the to and fro journey/Total time taken in the to and fro journey
= 18π / 2 = 9π km/hr
Answer is (C) 9π km/hr
