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# In a certain business, production index p is directly proportional to

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Joined: 02 Sep 2009
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Re: In a certain business, production index p is directly proportional to [#permalink]

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28 Dec 2017, 19:51
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akbankit wrote:
Hi Bunuel/Karishma

I solved this question and culminated in choice D as answer choice. I am posting my solution here, please help me with reason why i am wrong.

Statement 1 - e= 0.5 whenever i =60

per question stem we know that p is directly proportion to e and e is directly proportion to i , using this we can calculate P as 60*0.5 = 30 at e and i being 0.5 and 60 respectively; and to find the value of e (called e1) at i =70 . e = (0.5/60) *70 ---> 7/30 is the value of e (e1) at i = 70.

Now we can calculate p at i =70 using above relation = 30* (7/6) * (7/15)

where 7/6 is constant for i and 7/15 {7/(30*0.5)} is constant for e.

Using above i arrived at option D which is wrong. Please let me know me the pitfalls and where did i move away from the relevant concept.

Looking forward to hear from the Masters!!

So, you are calculating p as p = ei, which is wrong. $$p=ex$$ and $$e=iy$$ (for some constants $$x$$ and $$y$$), so $$p=ixy$$.

Not sure what you are doing in the part in red.

Please check correct approaches above. They should help to get the flaws in your logic.

Theory:
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Hope it helps.
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Re: In a certain business, production index p is directly proportional to   [#permalink] 28 Dec 2017, 19:51
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