QUICK QUANT QUESTION...

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by jbivins » Tue Sep 06, 2011 11:19 am
1/t = 5s/(s-t)

cross multiply and then simplify

s-t=5st
s=5st+t
s=t(5s+1)
s/(5s+1)=t

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by GMATGuruNY » Wed Sep 07, 2011 3:18 am
chris_usauru wrote:Sorry, this might be too easy, yet I can't find a way to answer the question. Here it goes:

What is T in terms of S?

S is NOT equal to T

1/t = 5s/(s-t)

we have:

a.- s/(5s+1)
b.- (5s+1)/s
c.- s/(5s-1)
d.- (5s-1)/s
e.- 5s

Any help??!
Let s=2.
1/t = (5*2)/(2-t)
2-t = 10t
2 = 11t
t = 2/11. This is our target.

Now we plug s=2 into the answers to see which yields our target of 2/11.

Only answer choice A works:
s/(5s+1)
= 2/((5*2) + 1)
= 2/11.

The correct answer is A.
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by prasad433 » Wed Sep 07, 2011 6:14 am
1/t=5s/(s-t)====> cross multiplication ==>(s-t)/t=5s
divide (s-t) by t gives (s/t)-1 right...move the 1 to other side
s/t=1+5s..so t= s=(1+5s)....

GMATGuruNY wrote:
chris_usauru wrote:Sorry, this might be too easy, yet I can't find a way to answer the question. Here it goes:

What is T in terms of S?

S is NOT equal to T

1/t = 5s/(s-t)

we have:

a.- s/(5s+1)
b.- (5s+1)/s
c.- s/(5s-1)
d.- (5s-1)/s
e.- 5s

Any help??!
Let s=2.
1/t = (5*2)/(2-t)
2-t = 10t
2 = 11t
t = 2/11. This is our target.

Now we plug s=2 into the answers to see which yields our target of 2/11.

Only answer choice A works:
s/(5s+1)
= 2/((5*2) + 1)
= 2/11.

The correct answer is A.

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by cans » Wed Sep 07, 2011 7:03 am
1/t = 5s/(s-t)
(s-t)/t = 5s
(s/t) = 5s + 1
t = s/(5s+1) IMO A
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by navami » Thu Sep 08, 2011 4:45 am
1/t = 5s/(s-t)

t = ( s - t) / 5 s

5ts = s - t
t(5s + 1) = s
t = s / (5s+1)
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