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Whenever martin has a restaurant bill with an amount between [#permalink]
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12 Feb 2011, 13:48
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69% (01:27) correct 31% (01:31) wrong based on 885 sessions
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Whenever martin has a restaurant bill with an amount between $10 and $99, he calculates the dollar amount of the tip as 2times the tens digit of the amount of his bill.If the amount of the Martin's most recent restaurant bill was between $10 and $99, was the tip calculated by the martin on this bill greater than 15 percent of the amount of the bill? (1) The amount of the bill was between $15 and $50 (2) The tip calculated by the martin was $8 1) as bill amount is between $15 and $50 tens digit can be any digit from 1,2,3,4
not sufficient
2) tip is 8 let y is the tens digit 2(y) = 8 y = 4 not sufficient
from 1 and 2
for any value of tens digit from 1 to 4 inclusive
and y=4
we can conclude that calculated tip ill be greater than the 15% of amount of bill
C
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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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12 Feb 2011, 14:21
GMATD11 wrote: whenever martin has a restaurant bill with an amount between $10 and $99, he calculates the dollar amount of the tip as 2times the tens digit of the amount of his bill. If the amount of the Martin's most recent restaurant bill was between $10 and $99, was the tip calculated by the martin on this bill greater than 15 percent of the amount of the bill?
1) The amount of the bill was between $15 and $50 2) The tip calculated by the martin was $8 C is not correct. You can solve this question algebraically but I think simple analysis would be better. (1) The amount of the bill was between $15 and $50 > 15<bill<50. Now if the bill was 20$ then the tip would be 2*2=$4 (2 times tens digit) so more than 0.15*20=$3 (15% of the bill) but if the bill was 29$ then the tip would still be 2*2=$4 but in this case less than 0.15*29=~$4.5. Not sufficient. (2) The tip calculated by the martin was $8 > Tip=$8 means that: 40<=bill<50 (so that the tens digit of the bill to be 4). Now, even if the bill was exactly $50 (uppert limit), 15% of it would be 0.15*50=$7.5 and it's still less than $8. So the answer to the question is YES: the tip (8$) was greater than 15% of the bill. Sufficient. Answer: B. Similar question: sallysbillgreaterthan25oftheamount108351.html
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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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12 Feb 2011, 15:14
yes, it has to be B. since the 15% of 50 is 7.5, and if the tip is 8, then the tip value between 40 to 50 will always be more than 7.5
where as for 1 the value can be less than 15% to more than 15%, depending if the amount is for example between 15 to 19, vs between 25 to 29



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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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31 May 2013, 05:43



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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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17 Oct 2013, 07:01
Bunuel wrote: GMATD11 wrote: whenever martin has a restaurant bill with an amount between $10 and $99, he calculates the dollar amount of the tip as 2times the tens digit of the amount of his bill. If the amount of the Martin's most recent restaurant bill was between $10 and $99, was the tip calculated by the martin on this bill greater than 15 percent of the amount of the bill?
1) The amount of the bill was between $15 and $50 2) The tip calculated by the martin was $8 C is not correct. You can solve this question algebraically but I think simple analysis would be better. (1) The amount of the bill was between $15 and $50 > 15<bill<50. Now if the bill was 20$ then the tip would be 2*2=$4 (2 times tens digit) so more than 0.15*20=$3 (15% of the bill) but if the bill was 29$ then the tip would still be 2*2=$4 but in this case less than 0.15*29=~$4.5. Not sufficient. (2) The tip calculated by the martin was $8 > Tip=$8 means that: 40<=bill<50 (so that the tens digit of the bill to be 4). Now, even if the bill was exactly $50 (uppert limit), 15% of it would be 0.15*50=$7.5 and it's still less than $8. So the answer to the question is YES: the tip (8$) was greater than 15% of the bill. Sufficient. Answer: B. Similar question: sallysbillgreaterthan25oftheamount108351.htmlHi Bunuel, for this question. In the first statement, how do you know what amount for the bill to choose in order to increase your odds of having a yes/no answer. Do you tipically look for a lower/middle or upper range? Thanks Cheers J



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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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17 Oct 2013, 08:38
jlgdr wrote: Bunuel wrote: GMATD11 wrote: whenever martin has a restaurant bill with an amount between $10 and $99, he calculates the dollar amount of the tip as 2times the tens digit of the amount of his bill. If the amount of the Martin's most recent restaurant bill was between $10 and $99, was the tip calculated by the martin on this bill greater than 15 percent of the amount of the bill?
1) The amount of the bill was between $15 and $50 2) The tip calculated by the martin was $8 C is not correct. You can solve this question algebraically but I think simple analysis would be better. (1) The amount of the bill was between $15 and $50 > 15<bill<50. Now if the bill was 20$ then the tip would be 2*2=$4 (2 times tens digit) so more than 0.15*20=$3 (15% of the bill) but if the bill was 29$ then the tip would still be 2*2=$4 but in this case less than 0.15*29=~$4.5. Not sufficient. (2) The tip calculated by the martin was $8 > Tip=$8 means that: 40<=bill<50 (so that the tens digit of the bill to be 4). Now, even if the bill was exactly $50 (uppert limit), 15% of it would be 0.15*50=$7.5 and it's still less than $8. So the answer to the question is YES: the tip (8$) was greater than 15% of the bill. Sufficient. Answer: B. Similar question: sallysbillgreaterthan25oftheamount108351.htmlHi Bunuel, for this question. In the first statement, how do you know what amount for the bill to choose in order to increase your odds of having a yes/no answer. Do you tipically look for a lower/middle or upper range? Thanks Cheers J Well, it depends on the question but to test extreme values might be a good thing to do. For this question, as the tip is tied to the tens digit of the bill, then I chose two extreme amounts which have the same tens digit so generate the same tip (20 and 29).
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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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18 May 2014, 10:59
Bill is XY and the tip is 2X
Question is :
Is 2x/(10x+Y) > 15/100 ?
Or if we simplfy this expression: Is 10X>3Y
Remember Y can be between 09 so 3y Can be 27 MAX ( 3x9)
So if 10X>27 X needs to be greater than 2 Exclamation
Statement 1) 1<x<5 INSUF Statement 2) tip = 8, so X = 4 which is greater than 2 SUF
Hence, B



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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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05 Oct 2014, 00:37
Bunuel wrote: Bumping for review and further discussion*. Get a kudos point for an alternative solution! *New project from GMAT Club!!! Check HEREGiven: Let A = amount of the bill, in which 10 < A < 99 Let T = tip Let t(A) = tens digit of the amount, > T = 2*t(A) Question: T > 15%(A)? 2*t(A) > 15%(A)? 2*t(A) > \(\frac{3}{20}\)*A? \(\frac{40}{3}\) > \(\frac{A}{t(A)}\)? (1) 15 < A < 30 If A = 20, t(A) = 2 \(\frac{40}{3}\) > \(\frac{20}{2}\)? Yes If A = 29, t(A) = 2 \(\frac{40}{3}\) > \(\frac{29}{2}\)? No Hence, insufficient. (2) T = 8 8 = 2*t(A) > 4=t*(A) > Possible values for T: 41, 42,...,49 If A = 49, t(A) = 4 \(\frac{40}{3}\) > \(\frac{49}{4}\)? Yes If A = 40, t(A) = 4 \(\frac{40}{3}\) > \(\frac{40}{4}\)? Yes Hence, sufficient. Answer: B



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Re: Whenever martin has a restaurant bill with an amount between [#permalink]
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14 Sep 2017, 21:31
Hi Bunuel, Actually for GMAT DS problems, statements never contradict each other. However this question, Statement 1 > total paid amount is between 15 and 30 Statement 2 > total paid amount is between 40 and 49 inclusive.
So each statement gives diff bill paid amount, contradicting each other. can this be so?



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14 Sep 2017, 21:39




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