During a certain week, a seal ate 50% of the first 80 smelt : GMAT Problem Solving (PS)
Check GMAT Club App Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 09 Dec 2016, 21:43

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# During a certain week, a seal ate 50% of the first 80 smelt

Author Message
TAGS:

### Hide Tags

Manager
Joined: 05 Nov 2012
Posts: 71
Schools: Foster '15 (S)
GPA: 3.65
Followers: 1

Kudos [?]: 115 [0], given: 8

During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

24 May 2013, 14:44
5
This post was
BOOKMARKED
00:00

Difficulty:

35% (medium)

Question Stats:

65% (02:40) correct 35% (01:46) wrong based on 228 sessions

### HideShow timer Statistics

During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80
[Reveal] Spoiler: OA

_________________

___________________________________________
Consider +1 Kudos if my post helped

Math Expert
Joined: 02 Sep 2009
Posts: 35932
Followers: 6861

Kudos [?]: 90104 [0], given: 10413

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

24 May 2013, 14:50
pikachu wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

Total smelt = x.

Then, 0.5*80+0.3(x-80)=0.4*x --> x=160 --> 0.4*x=64.

_________________
Intern
Joined: 15 Oct 2012
Posts: 25
Followers: 0

Kudos [?]: 13 [0], given: 1

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

25 May 2013, 02:34
Bunuel wrote:
pikachu wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

Total smelt = x.

Then, 0.5*80+0.3(x-80)=0.4*x --> x=160 --> 0.4*x=64.

Bunuel why I am getting a different answer?

Let say Total number of Smelt be - 100

Seal ate - 50% of 80 I.e 40
Than.....- 30% of remaining 20(100-80) I.e 6
Which comes to total of 46(40+6)

Now its given seal ate total of 40%....

In that case 46/40*100 comes to 115 total no of spate......

Where I am going wrong ...can you explain please???
Math Expert
Joined: 02 Sep 2009
Posts: 35932
Followers: 6861

Kudos [?]: 90104 [0], given: 10413

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

25 May 2013, 02:37
nikhilsehgal wrote:
Bunuel wrote:
pikachu wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

Total smelt = x.

Then, 0.5*80+0.3(x-80)=0.4*x --> x=160 --> 0.4*x=64.

Bunuel why I am getting a different answer?

Let say Total number of Smelt be - 100

Seal ate - 50% of 80 I.e 40
Than.....- 30% of remaining 20(100-80) I.e 6
Which comes to total of 46(40+6)

Now its given seal ate total of 40%....

In that case 46/40*100 comes to 115 total no of spate......

Where I am going wrong ...can you explain please???

The number of smelt is some particular number you cannot assume that it's 100.
_________________
Intern
Joined: 10 Dec 2010
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 5

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

23 May 2014, 01:45
Hi,

I am getting a different answer. My approach:
1. First Part - 80 smelts - 50% eaten = 40 ....... Statement 1
2. 2nd Part - x smelts - 30% eaten = 0.3x ....... Statement 2

Total Smelts = 1st part + 2nd part = 80+x
Seal ate 40% of total smelts => 0.4 (80+x) ....... Statement 3

Therefore , combining Statement 1,2,3
40 + 0.3x = 0.4(80+x) . This is giving x = 80 and 32 as the answer.

Kindly assist where I have gone wrong. Thanks
Math Expert
Joined: 02 Sep 2009
Posts: 35932
Followers: 6861

Kudos [?]: 90104 [0], given: 10413

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

23 May 2014, 02:04
mayankgc wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

Hi,

I am getting a different answer. My approach:
1. First Part - 80 smelts - 50% eaten = 40 ....... Statement 1
2. 2nd Part - x smelts - 30% eaten = 0.3x ....... Statement 2

Total Smelts = 1st part + 2nd part = 80+x
Seal ate 40% of total smelts => 0.4 (80+x) ....... Statement 3

Therefore , combining Statement 1,2,3
40 + 0.3x = 0.4(80+x) . This is giving x = 80 and 32 as the answer.

Kindly assist where I have gone wrong. Thanks

We are told that the seal ate 30% of the remaining smelt it came across. Thus x in your solution must be the number of the remaining smelt. Which makes the total number of smelt equal to 80 + x = 160. 40% of 160 is 64.

Does this make sense?
_________________
Intern
Joined: 10 Dec 2010
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 5

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

24 May 2014, 06:51
Yes it clears out my confusion
Thanks Bunuel...
Veritas Prep GMAT Instructor
Joined: 16 Oct 2010
Posts: 7076
Location: Pune, India
Followers: 2089

Kudos [?]: 13305 [0], given: 222

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

25 May 2014, 22:25
pikachu wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

Responding to a pm:

The seal ate 50% of first portion and 30% of second portion. Overall (average), it ate 40% of the entire portion.

Using scale method, Second portion/First portion = (50 - 40)/(40 - 30) = 1/1

So both portions need to be equal i.e. of 80 smelts each. So both portions together had 160 smelts and the seal ate 40% of it i.e. (40/100)*160 = 64 smelts
_________________

Karishma
Veritas Prep | GMAT Instructor
My Blog

Get started with Veritas Prep GMAT On Demand for \$199

Veritas Prep Reviews

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 12904
Followers: 562

Kudos [?]: 158 [0], given: 0

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

19 Sep 2015, 13:24
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Senior Manager
Joined: 05 Mar 2015
Posts: 448
Followers: 2

Kudos [?]: 56 [0], given: 35

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

21 May 2016, 23:09
pikachu wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

Let total no of smelts be X.
eaten smalts:- 50% of first 80==40 && 30 % of remaining (X-80)==30(X-80)/100
total 40% of X
40+ 30(X-80)/100=40X/100
X=160.
so eaten smelts= 40*160/100==64
Ans D.
Director
Joined: 18 Oct 2014
Posts: 924
Location: United States
GMAT 1: 660 Q49 V31
GPA: 3.98
Followers: 88

Kudos [?]: 219 [0], given: 69

Re: During a certain week, a seal ate 50% of the first 80 smelt [#permalink]

### Show Tags

22 May 2016, 10:15
pikachu wrote:
During a certain week, a seal ate 50% of the first 80 smelt it came across, and 30% of the remaining smelt it came across. If the seal ate 40% of the smelt it came across during the entire week, how many smelt did it eat?

A. 32
B. 40
B. 55
D. 64
E. 80

First the seal ate 50% of 80 i.e 40 smelt.

Suppose the number of remaining smelts is x. Seal then ate .30x of these remaining smelts.

Total smelts are 80+ x and seal ate 40% of 80+x

.4(80+x)= 40+.3x
x= 80

Total smelts eaten are .4(80+80)= 64

_________________

I welcome critical analysis of my post!! That will help me reach 700+

Re: During a certain week, a seal ate 50% of the first 80 smelt   [#permalink] 22 May 2016, 10:15
Similar topics Replies Last post
Similar
Topics:
1 During the first two weeks of January, the total rainfall in Springdal 2 16 Feb 2016, 00:02
1 During a certain two-week period, 70 percent of the movies rented from 4 20 Feb 2015, 02:43
4 During the first week of performances of a certain play 3 07 Dec 2013, 06:56
During the first 3 weeks of a 10-week diet program 9 15 Aug 2013, 08:49
17 During a certain season, a team won 80 percent of its first 9 20 Dec 2012, 07:20
Display posts from previous: Sort by