## Re: [2IIM CAT Prep] Ratio, proportions

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• lets anup s last yr salary be 2x and bunty s last yr salary be 3x......let this yr salary of anup and bunty be a and b respectively........now (2x)/a=3/4
Message 1 of 13 , Aug 3, 2011
 lets anup's last yr salary be 2x and bunty's last yr salary be 3x......let this yr salary of anup and bunty be a and b respectively........now (2x)/a=3/4 ->(1)        (3x/b)=5/7 ->(2)then a=8x/3       b=21x/5  difference in dis yr salary ie a-b=1150(8x/3) - (21x/5)=1150solving we get x=750   then bunty's dis yr salary  is 21x/5  = 3150
• data sufficiency If N is a natural number then number of factors of N^2 is ... A. N has 12 factors. B. N^3 has 70 factors. pls ans with xplanation
Message 2 of 13 , Aug 16, 2011
data sufficiency
If N is a natural number then number of factors of N^2 is ...

A. N has 12 factors.
B. N^3 has 70 factors.

pls ans with xplanation
• N has 12 factors = N can be of the form p^11 or p*q^5 or p^2 * q^3. So, this is not sufficient N^3 has 70 factors 70 can be written as 70 * 1 = N^3 = p^69
Message 3 of 13 , Aug 16, 2011
N has 12 factors => N can be of the form p^11 or p*q^5 or p^2 * q^3. So, this is not sufficient
N^3 has 70 factors

70 can be written as
70 * 1 => N^3 = p^69 possible => N = p^ 23
35 * 2 => N^3 =  p^34 * q  Not possible as this cannot be a perfect cube
5 * 14 => N^3 =  p^4 * q^13 Not possible as this cannot be a perfect cube
7 * 10 => N^3 = p^6 * q ^ 9 Possible => N = P^2 * q^3

So, this alone is not sufficient.

Both combined together, we can say N has to be of the form p^2 * q^3 and therefore number of factors of N^2 can be found.

Good question, but to be honest I do not think CAT will ask a question even as tough as this.

Cheers,
Rajesh
2IIM

On Wed, Aug 17, 2011 at 4:38 AM, mohit gupta wrote:

data sufficiency
If N is a natural number then number of factors of N^2 is ...

A. N has 12 factors.
B. N^3 has 70 factors.

pls ans with xplanation

• dere r 6 letters and 6 addressed envelops... what is the proabability that exactly 3 are in wrong envelops..
Message 4 of 13 , Aug 18, 2011
dere r 6 letters and 6 addressed envelops...

what is the proabability that exactly 3 are in wrong envelops..

• I think it should be 2400.. because you take 3 letters at random which is 6C3 then you multiply by the number of ways each will go in so 6*5*4 6C3*6*5*4 = 2400
Message 5 of 13 , Aug 19, 2011
I think it should be 2400..
because you take 3 letters at random which is 6C3 then you multiply by the number of ways each will go in so 6*5*4
6C3*6*5*4 = 2400

From: mohit gupta <mohit_luvkush@...>
To: "ascent4cat@yahoogroups.com" <ascent4cat@yahoogroups.com>
Sent: Friday, August 19, 2011 1:11 AM
Subject: Re: [2IIM CAT Prep] Ratio, proportions

dere r 6 letters and 6 addressed envelops...

what is the proabability that exactly 3 are in wrong envelops..

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