BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Working Independently

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 328
Joined: Thu Aug 07, 2008 5:25 pm
Location: Philadelphia
Thanked: 4 times
GMAT Score:550

Working Independently

by Abdulla » Fri Dec 12, 2008 4:51 pm
Working independently, Susan can perform a task in 6 hours and Tom can perform it in 7 hours. If Susan and Tom work together at the task for 3 hours, at which point Susan leaves, how many hours will it take tom to complete the task alone?

(A) 1/14
(B) 2/5
(C) 1/2
(D) 29/42
(E) 1

OA is C
Abdulla
Top
Source: — Problem Solving |
User avatar
Master | Next Rank: 500 Posts
Posts: 248
Joined: Mon Aug 11, 2008 9:51 am
Thanked: 13 times

by earth@work » Fri Dec 12, 2008 5:37 pm
Susan: 1 hour....... 1/6th work
Tom: 1 hour...........1/7th work
(tom+susan): 1 hour.........13/14th work
(tom+susan): 3 hour.........(13/14)*3 th work = 13/14
work left=1-13/14=1/14
Tom will take: (1/14)*7=1/2hour
answer C
Top
Legendary Member
Posts: 891
Joined: Sat Aug 16, 2008 4:21 am
Thanked: 27 times
Followed by:1 members
GMAT Score:660(

by 4meonly » Fri Dec 12, 2008 10:13 pm
earth@work wrote: (tom+susan): 1 hour.........13/14th work
(tom+susan): 3 hour.........(13/14)*3 th work = 13/14
Small corrections: :)
(tom+susan): 1 hour.........13/42th work
(tom+susan): 3 hour.........(13/42)*3 th work = 13/14
Top
User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pm
Thanked: 237 times
Followed by:25 members
GMAT Score:730

by logitech » Fri Dec 12, 2008 11:59 pm
3/6 + (3+x)/7 = 1

X=1/2
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
Top
Senior | Next Rank: 100 Posts
Posts: 45
Joined: Sun Nov 30, 2008 8:41 pm
Thanked: 4 times

by mrsmarthi » Tue Dec 16, 2008 10:35 pm
logitech wrote:3/6 + (3+x)/7 = 1

X=1/2
Wow....that's an excellent short cut. So far I was trying to solve these type of problems in the routine elaborate way.

Kudos to you.

With the type of answers that you provide, Can't believe that you are targeting for 680. :roll:

Cheers.
Top
Legendary Member
Posts: 891
Joined: Sat Aug 16, 2008 4:21 am
Thanked: 27 times
Followed by:1 members
GMAT Score:660(

by 4meonly » Wed Dec 17, 2008 5:06 am
logitech wrote:3/6 + (3+x)/7 = 1
X=1/2
:shock: SUPER!!!

logitech, please DO NOT schedule your GMAT till May!!!! We need you))))
Top
Legendary Member
Posts: 833
Joined: Mon Aug 04, 2008 1:56 am
Thanked: 13 times

Re: Working Independently

by vivek.kapoor83 » Wed Dec 17, 2008 5:30 am
Abdulla wrote:Working independently, Susan can perform a task in 6 hours and Tom can perform it in 7 hours. If Susan and Tom work together at the task for 3 hours, at which point Susan leaves, how many hours will it take tom to complete the task alone?

(A) 1/14
(B) 2/5
(C) 1/2
(D) 29/42
(E) 1

OA is C
Suppose there is 42 unit of work. In 1 hr Susan do = 7 units, in 1 hr TOm do = 6 units.
together = 13 unit in 1 hr
and in 3hr = 39 units.
now, 3 units of work is left and he do 6 units in 1hr
therefore in 30mins he ll do = 3 units
Hence C.
Top
User avatar
Legendary Member
Posts: 2134
Joined: Mon Oct 20, 2008 11:26 pm
Thanked: 237 times
Followed by:25 members
GMAT Score:730

by logitech » Wed Dec 17, 2008 8:38 am
4meonly wrote:
logitech wrote:3/6 + (3+x)/7 = 1
X=1/2
:shock: SUPER!!!

logitech, please DO NOT schedule your GMAT till May!!!! We need you))))
I will be around ;-)
LGTCH
---------------------
"DON'T LET ANYONE STEAL YOUR DREAM!"
Top
Post new topic Post Reply
• Page 1 of 1