Value of C ?

[jainrahul1985]

K = 35000/(250-2.5c)
where 100000 < K < 300000
Find value of c ?
1)19 2)29 3)39 4)49 e)59

[pradeepkaushal9518]

is there something wrong in the question? for any value of c K will be less than 100000

[kikor65]

I backed solved this with all the the given answers and nothing works; I even tried to plug the HIGHEST and LOWEST possible values for K and that did not give any answers that resemble the available ones. Although I am far from an expert, I believe that this question is flawed.

[debmalya_dutta]

wrong question

[gmatcrasher2010]

Something is wrong with the values given in the question, either for K or C.

[Stuart@KaplanGMAT]

K = 35000/(250-2.5c)
where 100000 < K < 300000
Find value of c ?
1)19 2)29 3)39 4)49 e)59

Let's start by simplifying the question to:

k = 35000/x

where 100000<k<300000

For this to be true, x must be a fraction (dividing by a fraction increases the value of the right side).

For example, if x = 1/5, then k=5*35000 = 175000

Solving for the two boundaries:

100000 = 35000/x
x = 35000/100000 = 35/100 = 7/20

300000 = 35000/x
x = 35000/300000 = 35/300 = 7/60

So:

7/60 < x < 7/20

Subbing back in:

7/60 < 250-2.5c < 7/20

Multiplying by 60:

7 < 15000 - 150c < 21

-14993 < -150c < -14979

14993 > 150c > 14979

14993/150 > c > 14979/150

Well, 15000/150 = 100, so c is going to be a bit less than 100. Fortunately, no answer choice matches.

I say "fortunately", because this is a patently ridiculous question that required way too much calculation to answer - you'll never see anything that crazy on the GMAT. The algebra is challenging, if you like that kind of thing (and hey, I'm an algebra geek, which is why I solved it), but certainly not something you'll need to do on Test Day.

What's the source?

[frank1]

Well
35000/x should give more than 100000
that means x must be less than 0
for x less than 0 c must be greater than 100

even if there were answer choice like 590,190 and all...
i think it would be bit long question and unsuitable for 2 minute solving as the expert Stuart Kovinsky has pointed out.....if it was really in GMAT i would have said 59(educated guess) ....nearest to correct answer ....lol