Target Test Prep 20% Off Flash Sale is on! Code: FLASH20

Redeem
Target Test Prep
5-Day Free Trial
5-day free, full-access trial TTP

Available with Beat the GMAT members only code

MORE DETAILS
Target Test Prep
Magoosh
Magoosh
Study with Magoosh GMAT prep

Available with Beat the GMAT members only code

MORE DETAILS
Magoosh

Stuck with these questions Please help

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 13
Joined: Wed Feb 01, 2012 9:41 pm

Stuck with these questions Please help

by intenseCK » Wed Apr 11, 2012 2:14 am
Hi Can anyone please help with these questions from Gmat Prep-
1) The rate of 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

Q.2-Three grades of milk;1%, 2% and 3% fat by volume. X gallons of 1%, y gallons of 2%, z gallons of 3% are mixed to give x+y+z gallons of 1.5%. what is X in terms of y and z?
A.y+3z
B.(Y+Z)/4
C. 2Y+3Z
D.3y+z
E.3y+4Z
Top
User avatar
Community Manager
Posts: 1060
Joined: Fri May 13, 2011 6:46 am
Location: Utrecht, The Netherlands
Thanked: 318 times
Followed by:52 members

by neelgandham » Wed Apr 11, 2012 2:42 am
Question #1: I have posted a solution here -> https://www.beatthegmat.com/proportion-q ... 09593.html
Question #2: https://www.beatthegmat.com/gmat-prep-1- ... 08623.html

Please let me know if you need any further help!
Anil Gandham
Welcome to BEATtheGMAT | Photography | Getting Started | BTG Community rules | MBA Watch
Check out GMAT Prep Now's online course at https://www.gmatprepnow.com/
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Wed Apr 11, 2012 3:35 am
intenseCK wrote:Hi Can anyone please help with these questions from Gmat Prep-
1) The rate of 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
Rate of a certain chemical reaction, R, is directly proportional A²/B
When the concentration of chemical B is increased by 100 percent, then concentration of chemical A also increases by, say, a%.
Then, R = A²/B = (aA)²/2B
A²/B = a²A²/2B
1 = a²/2
a² = 2
a = 1.4, which means there is 40% increase in the concentration of chemical A.

The correct answer is D.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 3835
Joined: Fri Apr 02, 2010 10:00 pm
Location: Milpitas, CA
Thanked: 1854 times
Followed by:523 members
GMAT Score:770

by Anurag@Gurome » Wed Apr 11, 2012 3:37 am
intenseCK wrote: Q.2-Three grades of milk;1%, 2% and 3% fat by volume. X gallons of 1%, y gallons of 2%, z gallons of 3% are mixed to give x+y+z gallons of 1.5%. what is X in terms of y and z?
A.y+3z
B.(Y+Z)/4
C. 2Y+3Z
D.3y+z
E.3y+4Z
The concentration of milk in the mixture would be 1% * x + 2% * y + 3% * z, which is also equal to 1.5% * (x + y + z)
So, x + 2y + 3z = 1.5x + 1.5y + 1.5z
0.5y + 1.5z = 0.5x
y + 3z = x

The correct answer is A.
Anurag Mairal, Ph.D., MBA
GMAT Expert, Admissions and Career Guidance
Gurome, Inc.
1-800-566-4043 (USA)

Join Our Facebook Groups
GMAT with Gurome
https://www.facebook.com/groups/272466352793633/
Admissions with Gurome
https://www.facebook.com/groups/461459690536574/
Career Advising with Gurome
https://www.facebook.com/groups/360435787349781/
Top
Junior | Next Rank: 30 Posts
Posts: 13
Joined: Wed Feb 01, 2012 9:41 pm

by intenseCK » Wed Apr 11, 2012 3:48 am
thanks a ton fellas
Top
Post new topic Post Reply
• Page 1 of 1