NEW HERE? LEARN MORE
close
It is currently 07 Feb 2023, 22:56
Register
GMAT Club Tests
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 sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately

15 posts Go to First Unread Post
Print view
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
SORT BY:
Date
Kudos
User avatar
GGUY
Manager
Manager
Joined: 26 Jun 2007
Posts: 53
The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  Updated on: 28 Nov 2014, 04:17
1
Kudos
4
Bookmarks
Quiz Dashboard Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
00:00
A
B
C
D
E

Difficulty:

15% (low)

Question Stats:

82% (01:40) correct 18% (01:46) wrong based on 516 sessions

Hide Show timer Statistics

The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately what percent of a day?

(A) 14%
(B) 16%
(C) 24%
(D) 28%
(E) 72%
ShowHide Answer
Official Answer
Official Answer and Stats are available only to registered users. Register/Login.

Originally posted by GGUY on 15 Jan 2008, 13:52.
Last edited by Bunuel on 28 Nov 2014, 04:17, edited 1 time in total.
Renamed the topic, edited the question, added the OA and moved to PS forum.
Quiz Dashboard Attempt only this question Same topic and source Same topic and difficulty Same source and difficulty Random Chronological Reverse chronological Learn more
User avatar
B
walker
SVP
SVP
Joined: 17 Nov 2007
Posts: 2463
Concentration: Entrepreneurship, Other
Schools: Chicago (Booth) - Class of 2011
GMAT 1: 750 Q50 V40
GMAT ToolKit User
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  15 Jan 2008, 14:03
1
Kudos
Expert Reply
D

30-sec way.

3h45+2h55= 5h(45+55)=5h(1h40)=6h40

100%*6h40/24h is between ~6*4/100~24% and ~7*4/100~28%
6h40 is closer to 7, therefore, D
_________________
HOT! GMAT Club Forum 2020 | GMAT ToolKit 2 (iOS) - The OFFICIAL GMAT CLUB PREP APPs, must-have apps especially if you aim at 700+
Signature Read More
User avatar
buffdaddy
Director
Director
Joined: 14 Oct 2007
Posts: 552
Location: Oxford
Schools:Oxford'10
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  15 Jan 2008, 14:13
2
Kudos
depends what you prefer...

i did it fairly quickly by converting 6hours 40mins to 400 mins. A quick multiplication in my head 24*6 yielded 144 ( since 12x12 = 144). So that told me a day had 1440 mins (approx 1500 to make it easier). 400 * 4 = 1600. so 400 is 25% of 1600, so it has to be a little over 25% of 1440. i.e 28%
User avatar
Travel09
Manager
Manager
Joined: 16 Dec 2007
Posts: 192
Location: San Diego,CA
Schools:Kellogg (R2), UCLA (R2)
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  15 Jan 2008, 18:23
2
Kudos
Since the question is asking for an approximate percentage

3:45+2:55 ~ 7 hours

% of day = 7*100/24 ~ 7*100/25= 28%

Answer is D.

If you had 27 and 29 as options you would probably need to do more accurate calculations. In this particular case while approximating values we increase both numerator and denominator so our calculations should be close
User avatar
rgajare14
Senior Manager
Senior Manager
Joined: 02 Aug 2007
Posts: 297
Location: Greater New York City area
Schools:Tuck, Ross (R1), Duke, Tepper, ISB (R2), Kenan Flagler (R2)
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  15 Jan 2008, 19:10
1
Kudos
Although I did it the way buffdaddy mentioned, I think the method that Travel09 mentioned would be the fastest.
avatar
GMATBLACKBELT
VP
VP
Joined: 29 Mar 2007
Posts: 1195
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  15 Jan 2008, 21:46
1
Kudos
GGUY wrote:
I discovered that doing the math is a time consuming effort, reflecting on my overall speed in the test. Attached a Q from GMAT Paper Test 48, a very simple one.
Anyway, I'd appreciate a method to do the arithmetics quickly.

The sum of 3 hours 45 minutes and 2 hours 55
minutes is approximately what percent of a day?

(A) 14%
(B) 16%
(C) 24%
(D) 28%
(E) 72%

OA will follow.


5 hrs and 55+45 minutes 6 hrs and 40 mintues --> 6 2/3 hr/24 --> 6/24 --> 1/4 so u know its going to be greater than 25%. Therfore only answer is D.

Or u can do 20/3/24 --> 20/72 -> 10/36 --> 5/18 ~28%.
avatar
marcodonzelli
Director
Director
Joined: 22 Nov 2007
Posts: 663
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  16 Jan 2008, 00:13
1
Kudos
GGUY wrote:
I discovered that doing the math is a time consuming effort, reflecting on my overall speed in the test. Attached a Q from GMAT Paper Test 48, a very simple one.
Anyway, I'd appreciate a method to do the arithmetics quickly.

The sum of 3 hours 45 minutes and 2 hours 55
minutes is approximately what percent of a day?

(A) 14%
(B) 16%
(C) 24%
(D) 28%
(E) 72%

OA will follow.


put everithing in minutes: 400/1440 equals 3 hours 45 minutes plus 2 hours 55. divide per 24*60 mins a day. therefore, simplify and obtain 250/9 which is somewhat less than 28.
User avatar
eschn3am
Senior Manager
Senior Manager
Joined: 12 Jul 2007
Posts: 420
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  16 Jan 2008, 04:51
1
Kudos
GGUY wrote:
I discovered that doing the math is a time consuming effort, reflecting on my overall speed in the test. Attached a Q from GMAT Paper Test 48, a very simple one.
Anyway, I'd appreciate a method to do the arithmetics quickly.

The sum of 3 hours 45 minutes and 2 hours 55
minutes is approximately what percent of a day?

(A) 14%
(B) 16%
(C) 24%
(D) 28%
(E) 72%

OA will follow.


Call 2 hours 55 minutes 3 hours. and round 3 hours 45 minutes down to 3 hours. Add them up and you get 6 hours. 24/6 = 1/4 but we rounded out 40 minutes, so the answer will be slightly higher than 25%. D is the only one that fits the bill. All in your head in a few seconds
User avatar
GGUY
Manager
Manager
Joined: 26 Jun 2007
Posts: 53
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  17 Jan 2008, 02:20
1
Kudos
eschn3am wrote:
Call 2 hours 55 minutes 3 hours. and round 3 hours 45 minutes down to 3 hours. Add them up and you get 6 hours. 24/6 = 1/4 but we rounded out 40 minutes, so the answer will be slightly higher than 25%. D is the only one that fits the bill. All in your head in a few seconds
eschn3am, thanks. does that mean you look at the answers before you solve?
Travel09 wrote:
Since the question is asking for an approximate percentage

3:45+2:55 ~ 7 hours

% of day = 7*100/24 ~ 7*100/25= 28%

Answer is D.

If you had 27 and 29 as options you would probably need to do more accurate calculations. In this particular case while approximating values we increase both numerator and denominator so our calculations should be close
I chose this one for me.

thanks all, each one got a kodus for his\hers efforts :lol:
User avatar
eschn3am
Senior Manager
Senior Manager
Joined: 12 Jul 2007
Posts: 420
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  17 Jan 2008, 04:57
I actually run it through like this to get a ballpark number right off the bat. Then I look at the numbers. If there's only one possible answer that works I choose it and go on. If the answers are more detailed (which rarely happens with these types of problem) I'll go back and try a more mathematical approach.
avatar
B
RajKomanapalli
Intern
Intern
Joined: 26 Jun 2017
Posts: 22
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  02 Dec 2019, 02:54
3H 45M and 2H 55M

adds up to 6H 40M


6H /24H = 25%

so our answer should be little over 25%

28% is the best fit for this question.
avatar
B
allezwart
Intern
Intern
Joined: 05 May 2020
Posts: 18
GPA: 3.72
Reviews Badge
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  09 Aug 2021, 18:49
Add the two times to get 6 hours and 40 mins. 40 mins is 2/3 of an hour. 6.67/24 is the answer. 6*4=24 so 6.67/24 is a little more than 25%.

D is the only answer that is a little more than 25%
User avatar
L
MathRevolution
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 11589
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  09 Aug 2021, 20:51
Sum is 6 hours 40 minutes: 6 * 60 + 40 = 400 minutes

In 1 day: 24 hours = 24 * 60 minutes

Percent: \(\frac{400 }{ 24} * 60 * 100 = 28%\)

Answer D
_________________
MathRevolution: The World's Most "Complete" GMAT Math Course!
Score an excellent Q49-51 just like 70% of our students.
[Free] On-demand trial course (7 days) - 100 hours of video lessons, 490 lesson topics, and 2,000 questions.
[Course] Starting at $79 for on-demand and $60 for tutoring per hour
Signature Read More
User avatar
L
MathRevolution
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 11589
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  09 Aug 2021, 20:54
Sum is 6 hours 40 minutes: 6 * 60 + 40 = 400 minutes

In 1 day: 24 hours = 24 * 60 minutes

Percent: \(\frac{400 }{ 24} * 60 * 100 = 28%\)

Answer D
_________________
MathRevolution: The World's Most "Complete" GMAT Math Course!
Score an excellent Q49-51 just like 70% of our students.
[Free] On-demand trial course (7 days) - 100 hours of video lessons, 490 lesson topics, and 2,000 questions.
[Course] Starting at $79 for on-demand and $60 for tutoring per hour
Signature Read More
User avatar
D
GMATCoachBen
Manager
Manager
Joined: 21 Mar 2017
Status:Professional GMAT Trainer
Affiliations: GMAT Coach
Posts: 183
Location: United States (WA)
GMAT 1: 760 Q50 V44
GMAT 2: 770 Q51 V44
GMAT 3: 770 Q50 V44
GMAT 4: 770 Q50 V45 (Online)
GMAT 5: 780 Q51 V48
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink] New post  21 Oct 2022, 16:03
eschn3am wrote:
GGUY wrote:
I discovered that doing the math is a time consuming effort, reflecting on my overall speed in the test. Attached a Q from GMAT Paper Test 48, a very simple one.
Anyway, I'd appreciate a method to do the arithmetics quickly.

The sum of 3 hours 45 minutes and 2 hours 55
minutes is approximately what percent of a day?

(A) 14%
(B) 16%
(C) 24%
(D) 28%
(E) 72%

OA will follow.


Call 2 hours 55 minutes 3 hours. and round 3 hours 45 minutes down to 3 hours. Add them up and you get 6 hours. 24/6 = 1/4 but we rounded out 40 minutes, so the answer will be slightly higher than 25%. D is the only one that fits the bill. All in your head in a few seconds


Yes, perfect solution. It's an important timesaving habit to use the answer choices to your advantage. When we notice that the question says "approximately", rounding and estimation are especially useful.
_________________
6 Principles for Effective GMAT Training: https://www.gmatcoach.com/our-approach/

Debrief/Online Format/Tips/Resources (online whiteboard, 770/Q50/V45) -- includes links to training/error log, books, distraction blockers, mindfulness tools, psychology tips, breathing exercises, reflection questions, etc

I offer online tutoring — please visit gmatcoach.com/trial to request a free initial consultation.
Signature Read More
GMAT Club Bot
gmatclubot
Re: The sum of 3 hours 45 minutes and 2 hours 55 minutes is approximately [#permalink]
21 Oct 2022, 16:03
NEW TOPIC
POST REPLY
Downloads
My Bookmarks
Reviews
Moderators:
chetan2u
Math Expert
10657 posts
Bunuel
Math Expert
88551 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3144 posts

cron

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