GMATprep DS question

Is the answer C?

1 says, S/S+B > s/s+b; Say S, B are later time numbers, s, b are from previous time numbers; this is insufficient since B could have decreased or S could have increased.

statment 2 says, S+B > s+b; INSUFFICIENT

combining them; for statement 1 to be true given that the S+B > s+b, S which is the numerator needs to be > s. = SUFFICEINT.

Somehow I'm thtinking I might have missed to consider some possibility. If anyone's see the obvious thing where I went wrong, please point at it. I'd appreciate it.

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Vignesh.4384: Master | Next Rank: 500 Posts; Posts: 443; Joined: Sat Jun 28, 2008 6:33 pm; Thanked: 5 times

by Vignesh.4384 » Sat Jul 05, 2008 8:56 pm

Hi ,

I think the answer is C.

Let there be S stocks and B bonds with Ruth.

Option A says :

The ratio of Stock to stcoks and bound increases.

i.e (S/S+B) increases.

for that ratio 2 increase either S should increase or B should decrease.
This option does not provide enough info.

Option B says :

The total no of S + B increases.
This also does not provide enough info.
either S could have increased or B could hav increased.

Combining both the option :

case 1) B cold hav increased while S is constan ( S+B increases)
but if this happened the ration (S/S+B) will not increase.
so B increasing when S is static is not a possibility.

Case 2) B increases S also increases ( S+ B increases) and ( also S/S+B increases )
So wen can say no of shares increase

Case 3) B decreases S increases
To comply with both the options S should increase by more than wat B decreses(S+ B shold increase) .

Case 4 ) B decreases S is constant.
this is not a possibility because S+B has 2 increase according 2 option B.

seeing cases 2 and 3 we can say that no of S will increase if both the conditions are to be satisfied.

i hope i am not confusing.

Regards,
Vignesh

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mlane25269: Master | Next Rank: 500 Posts; Posts: 151; Joined: Fri Jun 13, 2008 7:31 am; Thanked: 1 times

by mlane25269 » Sat Jul 05, 2008 9:33 pm

Thanks for the explanation Vanish but I'm still confused. Let me see if I'm understanding this question correctly...

In order for something to increase in a ratio either we have to know that either one of the values (the numerator or the denominator) is increasing/decreasing to know if something has decreased/increased???

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Vignesh.4384: Master | Next Rank: 500 Posts; Posts: 443; Joined: Sat Jun 28, 2008 6:33 pm; Thanked: 5 times

by Vignesh.4384 » Sat Jul 05, 2008 9:49 pm

Hi,

Consider this fraction a/b.
we can say that the ratio increases when
1)a increases b is constant
2)b decreases and a is constant
3)a increases and b decreases in the same time,

u really dont need to know the values of numerator or denominator.

Did i answer your question ??

If i did not please be more specific about what you dint understnad in this problem .

Last edited by Vignesh.4384 on Sat Jul 05, 2008 9:52 pm, edited 1 time in total.

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mlane25269: Master | Next Rank: 500 Posts; Posts: 151; Joined: Fri Jun 13, 2008 7:31 am; Thanked: 1 times

by mlane25269 » Sat Jul 05, 2008 9:50 pm

ok now that makes sense but I'm wondering if this is some kind of rule with fractions and ratios because I've never seen this in any of the GMAT math books I've read.

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Vignesh.4384: Master | Next Rank: 500 Posts; Posts: 443; Joined: Sat Jun 28, 2008 6:33 pm; Thanked: 5 times

by Vignesh.4384 » Sat Jul 05, 2008 9:58 pm

my advise ..
if u hav small doubts like these .. just take a pencil and paper and write down a fraction and play around with it. There is no better way to learn than doing it urself.
Not every thing is given in the test book