logs on the pile

This topic has expert replies
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

logs on the pile

by sanju09 » Thu May 13, 2010 5:55 am
Each hour, a wood-harvesting machine cuts the same number of logs and places them on a pile. At 8 am, there are 13 logs on the pile. At 11 am, the pile has grown to 46 logs. How many logs will the pile contain at 6 pm, the same evening?
(A) 108
(B) 112
(C) 117
(D) 123
(E) 135
Last edited by sanju09 on Fri May 14, 2010 12:46 am, edited 1 time in total.
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com

Master | Next Rank: 500 Posts
Posts: 487
Joined: Fri Mar 27, 2009 5:49 am
Thanked: 36 times

by dtweah » Thu May 13, 2010 7:01 am
8AM 9AM 10 AM 11AM ............. 6PM (18hrs)

13 13 +x 13+2x 13+3x =46..............112

13+3x=46
x=11

t10 ( 18hr -8hr=10) = 13+(10-1)11=112

Choose B

Junior | Next Rank: 30 Posts
Posts: 14
Joined: Fri May 07, 2010 3:54 am
Thanked: 1 times
GMAT Score:690

by GauravMalhotra » Thu May 13, 2010 10:41 am
dtweah wrote:8AM 9AM 10 AM 11AM ............. 6PM (18hrs)

13 13 +x 13+2x 13+3x =46..............112

13+3x=46
x=11

t10 ( 18hr -8hr=10) = 13+(10-1)11=112

Choose B
I am sorry.. I couldn;t quite follow your logic... I was getting answer as 123 which is obviously wrong and so I need to understand how you got 112.

User avatar
Legendary Member
Posts: 526
Joined: Sat Feb 21, 2009 11:47 pm
Location: India
Thanked: 68 times
GMAT Score:680

by harshavardhanc » Thu May 13, 2010 11:27 am
me too 123.... :(

is there something wrong?
Regards,
Harsha

Master | Next Rank: 500 Posts
Posts: 385
Joined: Sun Jul 12, 2009 10:16 pm
Thanked: 29 times
Followed by:2 members
GMAT Score:710

by debmalya_dutta » Thu May 13, 2010 11:38 am
I got 123 too .

:(

User avatar
GMAT Instructor
Posts: 3225
Joined: Tue Jan 08, 2008 2:40 pm
Location: Toronto
Thanked: 1710 times
Followed by:614 members
GMAT Score:800

by Stuart@KaplanGMAT » Thu May 13, 2010 12:04 pm
sanju09 wrote:Each hour, a wood-harvesting machine cuts the same number of logs and places them on a pile. At 8 am, there are 13 logs on the pile. At 11 am, the pile has grown to 46 logs. How many logs will the pile contain at 6 pm, the same evening?
(A) 108
(B) 112
(C) 117
(D) 126
(E) 135
46-13 is 33. 33 logs in 3 hours is 11 logs/hour.

From 11am until 6pm there are 7 hours. 7 * 11 = 77 new logs.

46 + 77 = 123, which is the correct answer to the question. What's the source?
Image

Stuart Kovinsky | Kaplan GMAT Faculty | Toronto

Kaplan Exclusive: The Official Test Day Experience | Ready to Take a Free Practice Test? | Kaplan/Beat the GMAT Member Discount
BTG100 for $100 off a full course

User avatar
Newbie | Next Rank: 10 Posts
Posts: 8
Joined: Mon May 10, 2010 1:40 pm
Location: Toronto, ON

by cager » Thu May 13, 2010 12:09 pm
i got 123
112 does not take into account the amount of logs made between 8am and 9am (according to the formula "13+(10-1)*11"

User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Fri May 14, 2010 12:45 am
Sorry pals for appearing so late on this thread, the OA is [spoiler](D) 123[/spoiler], which is by some typo, 126 there, I will edit it.

regards
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com