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Re: Yesterday's closing prices of 2,420 different stocks listed
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11 Mar 2017, 14:10
x higher prices y  lower prices
x=1,2 y x + y=2420 1,2y + y=2420 2,2y=2420 y=1100 x=1320 Hence, D



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Re: Yesterday's closing prices of 2,420 different stocks... (PS)
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18 Mar 2017, 21:29
Yesterday’s closing prices of all stocks were different from today’s closing prices. Therefore, all stocks were closed either at higher price or lower price and none closed at the same price. Now suppose, stocks closed at lower price = 100x; Then, stocks closed at higher price = 120x; So, 100x + 120x = 2420 =>220x = 2420 =>x = 2420/220 = 11. So, stocks closed at higher price = 120x = 120*11 = 1320. Answer D.
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Re: Yesterday's closing prices of 2,420 different stocks listed
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15 Apr 2017, 23:56
Yesterday's closing prices of 2,420 different stocks listed on a certain stock exchange were all different from today's closing prices. The number of stocks that closed at a higher price today than yesterday was 20 percent greater than the number that closed at a lower price. How many of the stocks closed at a higher price today than yesterday?
(A) 484 (B) 726 (C) 1,100 (D) 1,320 (E) 1,694
My 2 cents.
Initially, I could not set up an equation so I tried backsolving. I chose C first. If 1,100 is the higher price, then the lower price is 1,320. This is clearly wrong as we need higher price to be bigger than lower price by 20%.
D. If 1,320 is the higher price, then the lower price is 1,100. 20% higher than 1,100, should be 1,320. So this is the answer.



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Re: Yesterday's closing prices of 2,420 different stocks listed
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28 Apr 2017, 03:37
Hi all,
X = Higher Price
Y = Lower Price
X is 20% greater than Y => X = 1.2Y . This first thought is straightforward. I got it.
BUT, [ X is 20% greater than Y ] is equivalent to [ Y is 20% less than X ]
So, Y = 0.8X. This second thought will give a different answer.
Kindly clarify why the second thought, Y = 0.8X, is wrong.
Many thanks.



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Re: Yesterday's closing prices of 2,420 different stocks listed
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28 Apr 2017, 05:58
SISDIT wrote: Hi all,
X = Higher Price
Y = Lower Price
X is 20% greater than Y => X = 1.2Y . This first thought is straightforward. I got it.
BUT, [ X is 20% greater than Y ] is equivalent to [ Y is 20% less than X ]
So, Y = 0.8X. This second thought will give a different answer.
Kindly clarify why the second thought, Y = 0.8X, is wrong.
Many thanks. If X is 20% greater than Y, it is not the same as Y is 20% less than X. Note that the base is different in the two cases. When you say "X is 20% greater than Y", the base is Y X = Y + 20% of Y X is 20% greater than Y Say Y = 100 X = 100 + 20% of 100 = 120 When you say Y is 20% less than X, the base is X Y = X  20% of X Y is 20% less than X Say Y = 100 100 = X  20% of X 100 = 0.8X X = 125 Note that the value of X in the two cases is different.
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Re: Yesterday's closing prices of 2,420 different stocks listed
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19 Jul 2017, 04:50
Here the Question uses an SC Concept Ellipsis.The Ellipsed Noun Phrase is"today than yesterday".Read the Question as follows: Yesterday's closing prices of 2,420 different stocks listed on a certain stock exchange were all different from today's closing prices. The number of stocks that closed at a higher price today than yesterday was 20 percent greater than the number of stocks that closed at a lower price today than yesterday. How many of the stocks closed at a higher price today than yesterday?
Soln: Let x is the number of stocks that closed at a lower price, then 1.2x is the number of stocks that closed at a higher price. Given, the total number of stocks is 2,420, then x+1.2x=2,420 >> x=1,100, so 1.2x=1,320.
Answer: D.



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Re: Yesterday's closing prices of 2,420 different stocks listed
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29 Jul 2017, 03:32
Bunuel wrote: Yesterday's closing prices of 2,420 different stocks listed on a certain stock exchange were all different from today's closing prices. The number of stocks that closed at a higher price today than yesterday was 20 percent greater than the number that closed at a lower price. How many of the stocks closed at a higher price today than yesterday?
(A) 484 (B) 726 (C) 1,100 (D) 1,320 (E) 1,694
APPROACH #1:
Say \(x\) is the number of stocks that closed at a lower price, then \(1.2x\) is the number of stocks that closed at a higher price. Since the total number of stocks is 2,420, then \(x+1.2x=2,420\) > \(x=1,100\), so \(1.2x=1,320\).
Answer: D.
APPROACH #2:
If the number of stocks that closed at a lower price were the same as the number of stocks that closed at a higher price, then the number of stocks that closed at a higher price would be 2,420/2=1,210. Since we know that more stocks closed at a higher price than at a lower price than the answer must be greater than 1,210: eliminate A, B, and C. Now, E cannot be correct, because in this case 1,694 closed at a higher price and ~700 closed at a lower price, but 1,694 is obviously not 20% greater than ~700, so we are left with D.
Answer: D.
Hope it's clear. Hello Bunuel ! how about approach#3 i expressed so: 2420y+20%(2420y) where 2420y is stocks that have a lower price and 20%(2420y) is +20 % more . can you please say whats wrong is with my solution ?:)



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Re: Yesterday's closing prices of 2,420 different stocks listed
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29 Aug 2017, 03:45
I have confused here for example consider there are total 100 stocks. Then 20% of the stocked closed higher than the lower means there should be 60 stocks closed higher today and 40 stocks closed lower. The in 2420*60/100 = 1552 stocks right? Can anybody explain me what is wrong with this approach?
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Re: Yesterday's closing prices of 2,420 different stocks listed &nbs
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