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

Redeem

Target Test Prep · GMAT

Choose how you want to prepare

Learn live with an expert or move at your own pace. Every option includes the complete TTP study system.

★★★★★5.0559 reviews
GMATLiveTeach 7 seats left
Chris Peckover
NEXT LIVE COHORT

Oct 13 to Jan 7, 2027

with Chris Peckover

Schedule
Tue, Thu · 8:00 to 10:00 PM ET
Included
40 live hours + 6 months of GMAT OnDemand
  • Live instruction and real-time questions
  • Class recordings and assigned practice
View class & enroll
Limited cohort · enrollment openTarget Test Prep
EALiveTeach 5 seats left
Logan Thompson
EXECUTIVE ASSESSMENT

Sep 6 to Dec 6, 2026

with Logan Thompson

Schedule
Sun · 9:30 AM to 12:30 PM ET
Included
Live EA class + 6 months of EA OnDemand
  • Expert-led weekly online sessions
  • EA Masterclass access between classes
View EA class & enroll
Limited cohort · enrollment openTarget Test Prep
GMATOnDemand Start anytime
SELF-PACED MASTERCLASS

Target Test Prep GMAT OnDemand

Complete access from day one. Study on your schedule.

130-point score guarantee
$0to start then $127/mo
  • Personalized study plan and analytics
  • Thousands of lessons and practice questions
Start free 5-day trial
Read 559 reviewsTarget Test Prep

Compare the format, schedule, and included access before enrolling. Prices and seat counts shown reflect the supplied offer details.

GMAT PREP I PERCENT

Expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 266
Joined: Mon Oct 19, 2009 9:46 pm
Thanked: 8 times
GMAT Score:690
by pkw209 » Tue Dec 29, 2009 10:21 am
Hey all,

Couldn't figure this one out. A brief explanation would be very much appreciated. Thanks!

The rate of a reaction is directly proportional to the square of the concentration of A and inversely proportional to concentration of B. If B increases by 100%, which of the following is closest to the % change in concentration of A required to keep the rate unchanged?

a. 100% decrease
b. 50% decrease
c. 40% decrease
d. 40% increase
e. 50% increase
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Source: — Problem Solving |
Junior | Next Rank: 30 Posts
Posts: 11
Joined: Fri Dec 11, 2009 10:15 am
Thanked: 2 times

by anu009 » Tue Dec 29, 2009 11:24 am
is it d 40% increase
what is the answer
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Senior | Next Rank: 100 Posts
Posts: 98
Joined: Mon Nov 23, 2009 2:30 pmFollowed by: 1 member
Thanked: 26 times

by ace_gre » Tue Dec 29, 2009 11:32 am
Rate R = K * A^2 / B.
B==>2B( increase 100%), then R = K * A^2/ (2*B).

In order for R to be same, A==>√2 A==>1.414 A.
Hence ~ 41% increase in A will keep R the same.

I agree with anu009. Answer is D
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Master | Next Rank: 500 Posts
Posts: 266
Joined: Mon Oct 19, 2009 9:46 pm
Thanked: 8 times
GMAT Score:690

by pkw209 » Wed Dec 30, 2009 12:28 pm
thanks guys, you're both correct. answer is d

ace-can you please explain why you need to take the sqrt of 2A? i understand 2A but why the sqrt? I was able to figure this out by plugging in numbers but want to understand algebraically. thanks.
Top
Join the discussion
Log in to postLogin with Googleuse password
QUOTE IN REPLY
Post new topic Post Reply
• Page 1 of 1