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vineeshp: Legendary Member; Posts: 965; Joined: Thu Jan 28, 2010 12:52 amFollowed by: 34 members; Thanked: 156 times; GMAT Score:720

by vineeshp » Thu May 26, 2011 6:17 am

Vineesh,
Just telling you what I know and think. I am not the expert.

Source: Beat The GMAT — Critical Reasoning | Thu May 26, 2011 6:17 am

HSPA: Legendary Member; Posts: 1101; Joined: Fri Jan 28, 2011 7:26 amFollowed by: 13 members; Thanked: 47 times; GMAT Score:640

by HSPA » Thu May 26, 2011 6:22 am

IMO C

First take: 640 (50M, 27V) - RC needs 300% improvement
Second take: coming soon..
Regards,
HSPA.

sourabh33: Master | Next Rank: 500 Posts; Posts: 135; Joined: Tue Mar 22, 2011 12:01 pmFollowed by: 3 members; Thanked: 21 times; GMAT Score:720

by sourabh33 » Thu May 26, 2011 7:04 am

IMO E

cans: Legendary Member; Posts: 1309; Joined: Mon Apr 04, 2011 5:34 amFollowed by: 123 members; Location: India; Thanked: 310 times; GMAT Score:750

by cans » Thu May 26, 2011 7:38 am

E..
Conclusion - Less artificial fertilizers will be required if Rhizobium is hosted in wheat strains.
Assumption - Rhizobium living in roots of wheat would produce fixed nitrozen.

aftableo2006: Senior | Next Rank: 100 Posts; Posts: 99; Joined: Sat Oct 16, 2010 1:55 pm; Thanked: 1 times

by aftableo2006 » Thu May 26, 2011 7:51 am

i think the ans is D

dv2020: Master | Next Rank: 500 Posts; Posts: 112; Joined: Sun Nov 08, 2009 9:39 pm; Location: Delhi; Thanked: 2 times

by dv2020 » Thu May 26, 2011 9:25 am

The argument explicitly states in its conclusion that application of biotechnology will reduce the usage of fertilizers. Fertilizers are needed because some plants (non-legumes) don't have the rhizobium effect. That means there is no other way nutrient production in wheat plants can be improved and biotechnology offers an alternative to fertilizer application. C clearly negates the possibility of having any other alternatives.

IMO OA should be C

sanabk: Master | Next Rank: 500 Posts; Posts: 174; Joined: Fri Apr 02, 2010 3:41 pmFollowed by: 1 member; Thanked: 6 times

by sanabk » Thu May 26, 2011 1:53 pm

kevincanspain: GMAT Instructor; Posts: 613; Joined: Thu Mar 22, 2007 6:17 amFollowed by: 64 members; Location: madrid; Thanked: 171 times; GMAT Score:790

by kevincanspain » Thu May 26, 2011 2:15 pm

Rhizobium bacteria living in the roots of bean plants or other legumes produce fixed nitrogen which is one of the essential plant nutrients and which for non-legume crops, such as wheat normally must be supplied by applications of nitrogen-based fertilizer. So if biotechnology succeeds in producing wheat strains whose roots will play host to Rhizobium bacteria, the need for artificial fertilizers will be reduced.
The argument above makes which one of the following assumptions?
(A) Biotechnology should be directed toward producing plants that do not require artificial fertilizer.
(B) Fixed nitrogen is currently the only soil nutrient that must be supplied by artificial fertilizer for growing wheat crops.
(C) There are no naturally occurring strains of wheat or other grasses that have Rhizobium bacteria living in their roots.
(D) Legumes are currently the only crops that produce their own supply of fixed nitrogen.
(E) Rhizobium bacteria living in the roots of wheat would produce fixed nitrogen.

Remember, we are looking for a statement that MUST be true for the argument to be valid. A statement is an assumption underlying the argument if and only if its converse invalidates/severely weakens the argument.

The question we need to consider is the following: In light of the evidence provided, are we convinced that if biotechnology succeeds in producing wheat strains whose roots will play host to Rhizobium bacteria, the need for artificial fertilizers will be reduced?

(Note that the conclusion is NOT that any a need reduction must be a result of such production of wheat strains)

Whether C and D are true or false has no bearing on the argument. B would be a valid assumption if the conclusion used the word eliminate instead of reduce. However, if E is false (i.e. if the bacteria is the wheat roots would not produce fixed nitrogen), the conclusion would not make any sense at all!

Kevin Armstrong
GMAT Instructor
Gmatclasses
Madrid

kevincanspain: GMAT Instructor; Posts: 613; Joined: Thu Mar 22, 2007 6:17 amFollowed by: 64 members; Location: madrid; Thanked: 171 times; GMAT Score:790

by kevincanspain » Thu May 26, 2011 2:43 pm

How about a similar argument?

Mrs. Brown has hyperactive children with a lot of time of their hands. To keep them from getting in trouble, Mrs Brown has resorted to spending a lot of money on videogames and DVDs. She noticed the other day that her neighbours have hyperactive children who don't get into trouble: much of her neighbours' kids' time is spent playing with an adorable puppy. Mrs. Brown concluded that she would have to spend less money on videogames and DVDs if she adopted another puppy of the same litter.

Which of the following does Mrs Brown assume?

(A) Parents should adopt pets to keep their children out of trouble.
(B) The puppy would take up all of Mrs. Brown's children's spare time.
(C) Mr. Brown cannot be persuaded to spend more time with the kids.
(D) The children would not be amused by a cat or a pony.
(E) Mrs. Brown's children would be willing to play with a puppy.

Kevin Armstrong
GMAT Instructor
Gmatclasses
Madrid

vineeshp: Legendary Member; Posts: 965; Joined: Thu Jan 28, 2010 12:52 amFollowed by: 34 members; Thanked: 156 times; GMAT Score:720

by vineeshp » Thu May 26, 2011 6:47 pm

OA is E

Vineesh,
Just telling you what I know and think. I am not the expert.

dv2020: Master | Next Rank: 500 Posts; Posts: 112; Joined: Sun Nov 08, 2009 9:39 pm; Location: Delhi; Thanked: 2 times

by dv2020 » Thu May 26, 2011 11:40 pm

Thanks for the explanation of the above argumnent. Is the answer for this one also E

kevincanspain wrote:How about a similar argument?

Mrs. Brown has hyperactive children with a lot of time of their hands. To keep them from getting in trouble, Mrs Brown has resorted to spending a lot of money on videogames and DVDs. She noticed the other day that her neighbours have hyperactive children who don't get into trouble: much of her neighbours' kids' time is spent playing with an adorable puppy. Mrs. Brown concluded that she would have to spend less money on videogames and DVDs if she adopted another puppy of the same litter.

Which of the following does Mrs Brown assume?

(A) Parents should adopt pets to keep their children out of trouble.
(B) The puppy would take up all of Mrs. Brown's children's spare time.
(C) Mr. Brown cannot be persuaded to spend more time with the kids.
(D) The children would not be amused by a cat or a pony.
(E) Mrs. Brown's children would be willing to play with a puppy.

kevincanspain: GMAT Instructor; Posts: 613; Joined: Thu Mar 22, 2007 6:17 amFollowed by: 64 members; Location: madrid; Thanked: 171 times; GMAT Score:790

by kevincanspain » Sat May 28, 2011 6:09 am

dv2020 wrote:Thanks for the explanation of the above argumnent. Is the answer for this one also E
kevincanspain wrote:How about a similar argument?

Mrs. Brown has hyperactive children with a lot of time of their hands. To keep them from getting in trouble, Mrs Brown has resorted to spending a lot of money on videogames and DVDs. She noticed the other day that her neighbours have hyperactive children who don't get into trouble: much of her neighbours' kids' time is spent playing with an adorable puppy. Mrs. Brown concluded that she would have to spend less money on videogames and DVDs if she adopted another puppy of the same litter.

Which of the following does Mrs Brown assume?

Yes

(A) Parents should adopt pets to keep their children out of trouble.
(B) The puppy would take up all of Mrs. Brown's children's spare time.
(C) Mr. Brown cannot be persuaded to spend more time with the kids.
(D) The children would not be amused by a cat or a pony.
(E) Mrs. Brown's children would be willing to play with a puppy.

Kevin Armstrong
GMAT Instructor
Gmatclasses
Madrid

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