NEW HERE? LEARN MORE
closeclose
Last visit was: 26 Apr 2024, 06:14 It is currently 26 Apr 2024, 06:14
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

During a one-year study, biologists observed the number of fish in a ce

SORT BY:
Date
Kudos
Tags:
Find Similar Topics 
Show Tags
Hide Tags
User avatar
L
Bunuel
Math Expert
Joined: 02 Sep 2009
Posts: 92933
Own Kudos [?]: 619160 [0]
Given Kudos: 81609
Send PM
CAT Tests Forum Quiz Mode
During a one-year study, biologists observed the number of fish in a ce [#permalink] New post   15 Jul 2018, 08:54
Expert Reply
00:00
A
B
C
D
E

Difficulty:

15% (low)

Question Stats:

86% (01:35) correct 14% (01:24) wrong based on 54 sessions
Hide Show timer Statistics
During a one-year study, biologists observed the number of fish in a certain pond as well as the percent of the fish that were catfish. At the beginning of the year, there were 300 fish in the pond, of which 15 percent were catfish; and at the end of the year, there were 400 fish in the pond, of which 10 percent were catfish. From the beginning of the year to the end of the year, the number of catfish in the pond

A. decreased by more than 5%
B. decreased by 5%
C. did not change
D. increased by 5%
E. increased by more than 5%
ShowHide Answer
Official Answer
A
User avatar
L
chetan2u
RC & DI Moderator
Joined: 02 Aug 2009
Status:Math and DI Expert
Posts: 11180
Own Kudos [?]: 31947 [1]
Given Kudos: 290
Send PM
Reviews Badge
Re: During a one-year study, biologists observed the number of fish in a ce [#permalink] New post   15 Jul 2018, 18:16
1
Kudos
Expert Reply
Bunuel wrote:
During a one-year study, biologists observed the number of fish in a certain pond as well as the percent of the fish that were catfish. At the beginning of the year, there were 300 fish in the pond, of which 15 percent were catfish; and at the end of the year, there were 400 fish in the pond, of which 10 percent were catfish. From the beginning of the year to the end of the year, the number of catfish in the pond

A. decreased by more than 5%
B. decreased by 5%
C. did not change
D. increased by 5%
E. increased by more than 5%


Change in catfish 15% of 300 -10% of 400=\(300*\frac{15}{100}-400*\frac{10}{100}=45-40=5\)

Now all answer choices are related to 5% which actually means 5 in 100.
But here the decrease of 5 has been over 45, which is greater than 5 in 100.
Thus decreased by more than 5%

A
User avatar
P
LevanKhukhunashvili
Senior Manager
Senior Manager
Joined: 13 Feb 2018
Posts: 386
Own Kudos [?]: 385 [0]
Given Kudos: 50
GMAT 1: 640 Q48 V28
Send PM
Re: During a one-year study, biologists observed the number of fish in a ce [#permalink] New post   15 Jul 2018, 13:13
2003 --> 300 fish, 15% catfish. 300*0.15=45
2004 --> 400 fish, 10% catfish, 400*0.1=40

Decrease is obvious, lets calculate the % change
45-40=5 \(\frac{5}{45}\)*100~11%

IMO
Ans: A
GMAT Club Bot
gmatclubot
Re: During a one-year study, biologists observed the number of fish in a ce [#permalink]
15 Jul 2018, 13:13
Moderators:
Bunuel
Math Expert
92933 posts
yashikaaggarwal
Senior Moderator - Masters Forum
3137 posts

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