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If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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23 Aug 2012, 20:45
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If 10y  4 > 7 and y < 1, which of the following could be y? A. 0.8 B. 0.1 C. 0.1 D. 0 E. 1
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Last edited by Bunuel on 24 Aug 2012, 01:27, edited 2 times in total.
Renamed the topic and edited answer choices.



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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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23 Aug 2012, 20:54
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Please, write well your question. It seems that choices C and E are the same.
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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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13 Feb 2013, 11:58
why cant we get an answer by simply substituting values in the equation 10y  4 > 7



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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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13 Feb 2013, 12:31
mehasingh wrote: why cant we get an answer by simply substituting values in the equation 10y  4 > 7 In my opinion applying rules in modulus is much more easier than checking for multiple values. The rules are simple. 1) !x! < a > a < x < a so if !xa! < r then r < xa < r > ar < x < a+r 2) !x! > a > either x > a or x < a so if !Xa! > r then either xa > r > x > a+r or xa < r > x+a > r > x < ar Regards, Abhijit
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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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05 Jul 2013, 13:01
Bunuel wrote: laythesmack23 wrote: If 10y  4 > 7 and y < 1, which of the following could be y?
A. 0.8 B. 0.1 C. 0.1 D. 0 E. 1 We can simply plug answer choices less than 1 and see which one satisfies given inequality, or do the following: \(10y  4 > 7\) means that either \(10y4>7\) (when \(y>\frac{4}{10}\)) or \((10y4)>7\) (when \(y\leq{\frac{4}{10}}\)). Solve both inequalities: \(10y4>7\) > \(y>1.1\). Since we are told that \(y<1\), then discard this solution. \((10y4)>7\) > \(y<0.3\). Only answer choice which is less than 0.3 is 0.8. Answer: A. Hope it's clear. If I am not mistaken you have a typo in your explanation: 10y4>7 shall be y>11/10 not y>4/10.



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If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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05 Jul 2013, 13:10
rhallik wrote: Bunuel wrote: laythesmack23 wrote: If 10y  4 > 7 and y < 1, which of the following could be y?
A. 0.8 B. 0.1 C. 0.1 D. 0 E. 1 We can simply plug answer choices less than 1 and see which one satisfies given inequality, or do the following: \(10y  4 > 7\) means that either \(10y4>7\) (when \(y>\frac{4}{10}\)) or \((10y4)>7\) (when \(y\leq{\frac{4}{10}}\)). Solve both inequalities: \(10y4>7\) > \(y>1.1\). Since we are told that \(y<1\), then discard this solution. \((10y4)>7\) > \(y<0.3\). Only answer choice which is less than 0.3 is 0.8. Answer: A. Hope it's clear. If I am not mistaken you have typos in your explanation: 10y4>7 shall be y>11/10 not y>4/10. The same applies to (10y4)... No typo there. When \(y>\frac{4}{10}\), then we have \(10y4>7\) > \(y>\frac{11}{10}\). When \(y\leq{\frac{4}{10}}\)), then we have \((10y4)>7\) > \(y<\frac{3}{10}\). Hope it's clear.
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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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09 Jul 2013, 16:14
If 10y  4 > 7 and y < 1, which of the following could be y?
10y  4 > 7 10(.8)  4 > 7 84 > 7 12 > 7 12 > 7 12 > 7
(A)



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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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18 Jun 2017, 02:43
rhallik wrote: Bunuel wrote: laythesmack23 wrote: If 10y  4 > 7 and y < 1, which of the following could be y?
A. 0.8 B. 0.1 C. 0.1 D. 0 E. 1 We can simply plug answer choices less than 1 and see which one satisfies given inequality, or do the following: \(10y  4 > 7\) means that either \(10y4>7\) (when \(y>\frac{4}{10}\)) or \((10y4)>7\) (when \(y\leq{\frac{4}{10}}\)). Solve both inequalities: \(10y4>7\) > \(y>1.1\). Since we are told that \(y<1\), then discard this solution. \((10y4)>7\) > \(y<0.3\). Only answer choice which is less than 0.3 is 0.8. Answer: A. Hope it's clear. If I am not mistaken you have a typo in your explanation: 10y4>7 shall be y>11/10 not y>4/10. Bunuel how are you getting the y > 4/10?



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Re: If 10y4 > 7 and y < 1, which of the following could be y? [#permalink]
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18 Jun 2017, 02:56
Nunuboy1994 wrote: rhallik wrote: Bunuel wrote: If 10y  4 > 7 and y < 1, which of the following could be y?
A. 0.8 B. 0.1 C. 0.1 D. 0 E. 1
We can simply plug answer choices less than 1 and see which one satisfies given inequality, or do the following:
\(10y  4 > 7\) means that either \(10y4>7\) (when \(y>\frac{4}{10}\)) or \((10y4)>7\) (when \(y\leq{\frac{4}{10}}\)).
Solve both inequalities: \(10y4>7\) > \(y>1.1\). Since we are told that \(y<1\), then discard this solution.
\((10y4)>7\) > \(y<0.3\). Only answer choice which is less than 0.3 is 0.8.
Answer: A.
Hope it's clear. If I am not mistaken you have a typo in your explanation: 10y4>7 shall be y>11/10 not y>4/10. Bunuel how are you getting the y > 4/10? 4/10 is a transition point for 10y4 (transition point is a value of a variable for which expression in absolute value changes its sign). When \(y>\frac{4}{10}\), then 10y  4 > 0, so 10y  4 = 10y  4. When \(y\leq{\frac{4}{10}}\), then 10y  4 <= 0, so 10y  4 = (10y  4).
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