Oct 22 09:00 AM PDT  10:00 AM PDT Watch & learn the Do's and Don’ts for your upcoming interview Oct 22 08:00 PM PDT  09:00 PM PDT On Demand for $79. For a score of 4951 (from current actual score of 40+) AllInOne Standard & 700+ Level Questions (150 questions) Oct 23 08:00 AM PDT  09:00 AM PDT Join an exclusive interview with the people behind the test. If you're taking the GMAT, this is a webinar you cannot afford to miss! Oct 26 07:00 AM PDT  09:00 AM PDT Want to score 90 percentile or higher on GMAT CR? Attend this free webinar to learn how to prethink assumptions and solve the most challenging questions in less than 2 minutes. Oct 27 07:00 AM EDT  09:00 AM PDT Exclusive offer! Get 400+ Practice Questions, 25 Video lessons and 6+ Webinars for FREE.
Author 
Message 
TAGS:

Hide Tags

Manager
Joined: 05 Nov 2012
Posts: 138

Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
Updated on: 20 Dec 2012, 02:32
Question Stats:
50% (01:14) correct 50% (01:12) wrong based on 538 sessions
HideShow timer Statistics
Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar? A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes Source: HULT
Official Answer and Stats are available only to registered users. Register/ Login.
Originally posted by Amateur on 19 Dec 2012, 23:40.
Last edited by Bunuel on 20 Dec 2012, 02:32, edited 1 time in total.
Edited the question.



Manager
Joined: 05 Nov 2012
Posts: 138

Re: Danny and Ian are munching on a jar full of candies.
[#permalink]
Show Tags
19 Dec 2012, 23:42
I thought it should be inverse of the combined rates which is (10*5)/(10+5)=50/15=3+ minutes right? OA says a different one.... what am I doing wrong?



Director
Joined: 25 Apr 2012
Posts: 660
Location: India
GPA: 3.21
WE: Business Development (Other)

Re: Danny and Ian are munching on a jar full of candies.
[#permalink]
Show Tags
19 Dec 2012, 23:52
Amateur wrote: Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?
2.5 minutes
3 minutes
3 minutes and 20 seconds
6 minutes and 40 seconds
4 minutes
Source: HULT Hi, Danny's does in 5 minutes Ian finishes half in 10 minutes i.e finishes the jar in 20 minutes Therefore Combined rate will be 1/5+1/20=1/T 5/20= 1/T ==> T = 4 min
_________________
“If you can't fly then run, if you can't run then walk, if you can't walk then crawl, but whatever you do you have to keep moving forward.”



Math Expert
Joined: 02 Sep 2009
Posts: 58421

Re: Danny and Ian are munching on a jar full of candies.
[#permalink]
Show Tags
20 Dec 2012, 02:36
Amateur wrote: I thought it should be inverse of the combined rates which is (10*5)/(10+5)=50/15=3+ minutes right? OA says a different one.... what am I doing wrong? We are told that Ian needs 10 minutes to finish HALF the jar, so he needs 20 minute to finish full jar. Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes The rate of Danny is 1/5 jar/minute and the rate of Ian is 1/20 jar/minute, their combined rate is 1/5+1/20=1/4 jar/minute. Thus together they need 4 minutes to finish the jar. Answer: E.
_________________



EMPOWERgmat Instructor
Status: GMAT Assassin/CoFounder
Affiliations: EMPOWERgmat
Joined: 19 Dec 2014
Posts: 15294
Location: United States (CA)

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
28 Feb 2015, 14:15
Hi All, This question is essentially a "Work Formula" question, since it has 2 people working on a task together. You have to be really careful with the details though, since the two given rates are NOT for the same task.... We're told that Danny can finish off the jar of candies in 5 minutes We're told that Ian can finish off HALF the jar of candies in 10 minutes, which means that he can finish the WHOLE jar in 20 minutes. We're asked how long it would take the two of them to finish the jar of candies together.... Work = (A)(B)/(A+B) where A and B are the individual rates of the two entities. A = 5 B = 20 (5)(20)/(5+20) = 100/25 = 4 minutes to finish off the jar of candies. Final Answer: GMAT assassins aren't born, they're made, Rich
_________________
Contact Rich at: Rich.C@empowergmat.comThe Course Used By GMAT Club Moderators To Earn 750+ souvik101990 Score: 760 Q50 V42 ★★★★★ ENGRTOMBA2018 Score: 750 Q49 V44 ★★★★★



Retired Moderator
Joined: 29 Apr 2015
Posts: 822
Location: Switzerland
Concentration: Economics, Finance
WE: Asset Management (Investment Banking)

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
16 Jul 2015, 02:03
Bunuel wrote: Amateur wrote: I thought it should be inverse of the combined rates which is (10*5)/(10+5)=50/15=3+ minutes right? OA says a different one.... what am I doing wrong? We are told that Ian needs 10 minutes to finish HALF the jar, so he needs 20 minute to finish full jar. Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes The rate of Danny is 1/5 jar/minute and the rate of Ian is 1/20 jar/minute, their combined rate is 1/5+1/20=1/4 jar/minute. Thus together they need 4 minutes to finish the jar. Answer: E. OMG, actually this is a very simple question  the only problem here: if you go too fast and ignore the details, you will fail! (Finish HALF the jar...). With this trap this question becomes a 700+ question?!
_________________
Saving was yesterday, heat up the gmatclub.forum's sentiment by spending KUDOS!
PS Please send me PM if I do not respond to your question within 24 hours.



Intern
Joined: 11 Aug 2013
Posts: 24
Location: India
Concentration: Finance, General Management
GPA: 3.23
WE: Information Technology (Investment Banking)

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
18 Jul 2015, 09:32
this is a straight forward rate question Rate of danny finishing the jar = 1/5 J/min Rate of Ian finishing the jar = 1/20 J/min. when both eating together = (1/5 +1/20) J/min =>1/4 J/min Hence they can together eat the whole jar in 4 mins
_________________
Thanks Sindbad  Click +1 Kudos if my post helped...



Retired Moderator
Joined: 29 Apr 2015
Posts: 822
Location: Switzerland
Concentration: Economics, Finance
WE: Asset Management (Investment Banking)

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
23 Jul 2015, 21:38
Amateur wrote: Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?
A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes
Source: HULT Plug in a good number for the number of candies. E.g. 10 and set up a rate work table: Danny: Rate 2 / Time 5 / Work 10 Ian: Rate 0.5 / Time 10 / Work 5 Combined Rate: 2.5 / Time 4 / Work 10 Answer E
_________________
Saving was yesterday, heat up the gmatclub.forum's sentiment by spending KUDOS!
PS Please send me PM if I do not respond to your question within 24 hours.



SVP
Joined: 26 Mar 2013
Posts: 2344

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
13 Mar 2018, 16:33
Amateur wrote: Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?
A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes
Source: HULT Lot of way to solve but it is not 700 question. Danny's time to eat = 5 min & Ian's time to eat = 20 min With number sense, Dan is faster than Ian by 4 times....So it ill take him slightly less 5 minute to finish the candy jar. Let number of candies =20 Rate of Danny = 20/5 =4 Rate pf Ian = 20/20 =1 rate * time =work 5 * T =20....T = 4 minutes Answer: E



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8117
Location: United States (CA)

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
27 Jan 2019, 19:35
Amateur wrote: Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?
A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes Danny’s rate is 1/5, and Ian’s rate is (1/2)/10. Thus, their combined rate is: 1/5 + (1/2)/10 = 1/5 + 1/20 = 4/20 + 1/20 = 5/20 = 1/4 So it would take them 1/(1/4) = 4 minutes to eat the whole jar of candies together. Answer: E
_________________
5star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews If you find one of my posts helpful, please take a moment to click on the "Kudos" button.



Intern
Joined: 10 Jul 2016
Posts: 44

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
27 Jan 2019, 21:36
Amateur wrote: Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?
A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes
Source: HULT Simple formula to be used for work rate problems  Rate * Time = Work Whenever, work isnt specified  we can imagine it to be = 1 Using the formula  Danny's rate * 5minutes = 1, so danny/s rate = 1/5 Ian's rate * 10 = 1/2, so Ian/s rate = 1/20 The rate together would be 1/5 + 1/20 = 5/20 = 1/4 Hence, (rate together) * time = 1 1/4 * time = 1 Time = 4 minutes. Hence, answer is E.



Intern
Joined: 10 Jul 2016
Posts: 44

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
27 Jan 2019, 21:37
ScottTargetTestPrep wrote: Amateur wrote: Danny and Ian are munching on a jar full of candies. Had Danny eaten alone it would have taken him 5 minutes to finish the candies in the jar. Had Ian eaten alone it would have taken him 10 minutes to finish half the jar. Since both of them are eating simultaneously, how long would it take them to empty the jar?
A. 2.5 minutes B. 3 minutes C. 3 minutes and 20 seconds D. 6 minutes and 40 seconds E. 4 minutes Danny’s rate is 1/5, and Ian’s rate is (1/2)/10. Thus, their combined rate is: 1/5 + (1/2)/10 = 1/5 + 1/20 = 4/20 + 1/20 = 5/20 = 1/4 So it would take them 1/(1/4) = 4 minutes to eat the whole jar of candies together. Answer: E I've always had problems with work rate problems  but you guy have made it so simple for me, Scott. TTP is AWESOME!!



Target Test Prep Representative
Status: Founder & CEO
Affiliations: Target Test Prep
Joined: 14 Oct 2015
Posts: 8117
Location: United States (CA)

Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
Show Tags
31 Jan 2019, 18:23
Thank you! Glad we could help!
_________________
5star rated online GMAT quant self study course See why Target Test Prep is the top rated GMAT quant course on GMAT Club. Read Our Reviews If you find one of my posts helpful, please take a moment to click on the "Kudos" button.




Re: Danny and Ian are munching on a jar full of candies. Had Dan
[#permalink]
31 Jan 2019, 18:23






