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

Redeem

how to compare

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 am
Thanked: 85 times
Followed by:3 members

how to compare

by clock60 » Fri Jul 30, 2010 12:13 pm
hi guys
can somebody help me with problems like that:
how to compare
10^10 and 2^34
or
31^11 and 17^14
or
2^40 and 3^28

seriously it is not a joke and not for practice purposes, i faced very similar in MG, and solve the problem wrong.
Top
Source: — Problem Solving |

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Fri Jul 30, 2010 2:44 pm
clock60 wrote:hi guys
can somebody help me with problems like that:
how to compare
10^10 and 2^34
or
31^11 and 17^14
or
2^40 and 3^28

seriously it is not a joke and not for practice purposes, i faced very similar in MG, and solve the problem wrong.
I'm not sure what you mean by "compare"

For example, to we compare 2 and 6, we could say that 6 is 4 greater than 2, or we could say that 6 is 3 times 2.
Can you provide an actual GMAT question?
Brent Hanneson - Creator of GMATPrepNow.com
Image
Top
Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 am
Thanked: 85 times
Followed by:3 members

by clock60 » Sat Jul 31, 2010 3:14 am
hi Brent
thank you for reply.
below is problem. i know that it is DS problem, so must be posted in DS section. but i am interested in the approach here

Is x > 10^10 ?
(1) x > 2^34
(2)(2) x = 2^35
oa is D the source manhattan CAT
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Sat Jul 31, 2010 3:48 am
clock60 wrote:hi Brent
thank you for reply.
below is problem. i know that it is DS problem, so must be posted in DS section. but i am interested in the approach here

Is x > 10^10 ?
(1) x > 2^34
(2)(2) x = 2^35
oa is D the source manhattan CAT

(1) 2^34 = 2^ (3.4 × 10) = (2^3.4) ^10, and since a rough estimation could make us believe that 2^3.4 is greater than 10, hence anything more than 2^34 is got to be greater than 10^10. Sufficient

(2) The explanation above in (1) helps us call this too sufficient.

[spoiler]D[/spoiler]
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Legendary Member
Posts: 759
Joined: Mon Apr 26, 2010 10:15 am
Thanked: 85 times
Followed by:3 members

by clock60 » Sat Jul 31, 2010 4:28 am
hi sanju09
your solving is too smart for me,( i am sure that it is valid)
i want to replicate with my own words

2^34=2^(3,4*10)=(2^3,4)^10 we need to compare with 10^10

2^3,4=(10+x) where x is any positive number

so (10+x)^10>10^10
and it happens that 2^34>10^10
i see it is genious

but how you guess that 2^3.4>10
it is really 10.556
anyway many many thanks
Top
User avatar
GMAT Instructor
Posts: 3650
Joined: Wed Jan 21, 2009 4:27 am
Location: India
Thanked: 267 times
Followed by:80 members
GMAT Score:760

by sanju09 » Sat Jul 31, 2010 4:42 am
clock60 wrote:hi sanju09
your solving is too smart for me,( i am sure that it is valid)
i want to replicate with my own words

2^34=2^(3,4*10)=(2^3,4)^10 we need to compare with 10^10

2^3,4=(10+x) where x is any positive number

so (10+x)^10>10^10
and it happens that 2^34>10^10
i see it is genious

but how you guess that 2^3.4>10
it is really 10.556
anyway many many thanks
2^3.4 = 4^1.7, which is faintly less than the square of 4, not enough that could take 16 below 10 in any case, it's a sheer ballpark figure to make persuaded about something else rather than the exact value.
The mind is everything. What you think you become. -Lord Buddha



Sanjeev K Saxena
Quantitative Instructor
The Princeton Review - Manya Abroad
Lucknow-226001

www.manyagroup.com
Top
Post new topic Post Reply
• Page 1 of 1