NEW HERE? LEARN MORE
closeclose
Last visit was: 25 Apr 2024, 02:19 It is currently 25 Apr 2024, 02:19
Decision Tracker
My Rewards
New posts
New comers' posts

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

The hour hand of a clock is 3 feet long. How many feet does the tip of

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92912
Own Kudos [?]: 618882 [2]
Given Kudos: 81595
Send PM
CAT Tests Forum Quiz Mode
The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   01 Dec 2020, 10:45
2
Bookmarks
Expert Reply
00:00
A
B
C
D
E

Difficulty:

45% (medium)

Question Stats:

57% (01:39) correct 43% (01:53) wrong based on 43 sessions
Hide Show timer Statistics
The hour hand of a clock is 3 feet long. How many feet does the tip of this hand move between 9:30 P.M. and 1:30 A.M. the following day?

(A) π
(B) 2π
(C) 3π
(D) 4π
(E) 24π
ShowHide Answer
Official Answer
B
avatar
B
UsamaGuddar
Intern
Intern
Joined: 04 Sep 2020
Posts: 35
Own Kudos [?]: 7 [0]
Given Kudos: 8
Send PM
The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   01 Dec 2020, 10:55
Can we safely assume that the hour hand is equal to the radius of the circles?

If so, the answer is 4 times circumference = 24 pi

Posted from my mobile device
User avatar
G
TestPrepUnlimited
Tutor
Joined: 17 Sep 2014
Posts: 1251
Own Kudos [?]: 938 [0]
Given Kudos: 6
Location: United States
GMAT 1: 780 Q51 V45
GRE 1: Q170 V167
Send PM
Re: The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   01 Dec 2020, 15:37
Expert Reply
Bunuel wrote:
The hour hand of a clock is 3 feet long. How many feet does the tip of this hand move between 9:30 P.M. and 1:30 A.M. the following day?

(A) π
(B) 2π
(C) 3π
(D) 4π
(E) 24π


We can write 1:30 a.m. as 13:30 a.m. just to do the subtraction, so we know 13-9 = 4 hours have passed. The hour hand moved 4 circumferences in total, each circumference is \(2*\pi*r = 2\pi*3 = 6\pi\) so in total it is \(24\pi\).

Ans: E
User avatar
B
justbegan
Intern
Intern
Joined: 13 Nov 2020
Posts: 13
Own Kudos [?]: 9 [0]
Given Kudos: 23
Location: India
Schools: Booth '24 CEIBS '24 Haas '24 Harvard '24 HKUST IMD '22 ISB '23 LBS '24 NUS Rotman '24 Sloan '24 Smeal Kellogg '24 Tuck '24 Yale '24
Send PM
Re: The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   01 Dec 2020, 22:54
are you sure? i guess only minute hand will move that much. hour hand will be on 1 finally.
avatar
harsh1111
Intern
Intern
Joined: 04 Nov 2020
Posts: 1
Own Kudos [?]: 0 [0]
Given Kudos: 0
Send PM
Re: The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   02 Dec 2020, 05:28
I think the hour hand will move 1/12*360= 30° in 1 hour so it will move 120° in 4 hours which is 2πr/3 = 2*π*3/3 = 2π

Posted from my mobile device
avatar
B
UsamaGuddar
Intern
Intern
Joined: 04 Sep 2020
Posts: 35
Own Kudos [?]: 7 [0]
Given Kudos: 8
Send PM
Re: The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   02 Dec 2020, 05:30
Harsh I think your confusing the area covered w distance travelled

Posted from my mobile device
avatar
B
urmi760
Intern
Intern
Joined: 15 Apr 2020
Posts: 9
Own Kudos [?]: 2 [0]
Given Kudos: 26
Send PM
Re: The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink] New post   02 Dec 2020, 05:55
The correct answer is B (2pi).

In one hour, an hour hand moves 30 degrees (360/12), so in 4 hours it will move by 120 degrees.

Distance travelled by the tip of an hour hand = 120/360 * 2 * pi * r = 1/3 * 2 *pi * 3 = 2*pi
GMAT Club Bot
gmatclubot
Re: The hour hand of a clock is 3 feet long. How many feet does the tip of [#permalink]
02 Dec 2020, 05:55
Moderators:
Bunuel
Math Expert
92904 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne
Main navigation
GMAT Resources
Partners
MBA Resources
www.gmac.com|www.mba.com | | GMAT Club Rules | Terms and Conditions