Author 
Message 
TAGS:

Hide Tags

Director
Joined: 22 Mar 2011
Posts: 607
WE: Science (Education)

No wonder Federer lost in his Olympic tennis final, he [#permalink]
Show Tags
06 Aug 2012, 06:46
2
This post received KUDOS
3
This post was BOOKMARKED
Question Stats:
45% (01:52) correct 55% (02:06) wrong based on 86 sessions
HideShow timer Statistics
No wonder Federer lost in his Olympic tennis final, he previously played an exhausting semifinal match against Del Potro. In the third set, since there was no tiebreaker, after 6:6 they continued to play until one of the players first reached an advantage of 2 games (or in other words, won two consecutive games). What was the score in the final, decisive third set (which Federer won)? (1) The square of the average number of games won by Federer and Del Potro is a three digit number of the form BAC, where A,B, and C are nonzero consecutive digits. (2) Each played less than 50 games, the two numbers representing their final scores are consecutive prime numbers, whose sum is a perfect square.
Official Answer and Stats are available only to registered users. Register/ Login.
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Manager
Joined: 05 Jul 2012
Posts: 74
Location: India
Concentration: Finance, Strategy
GMAT Date: 09302012
GPA: 3.08
WE: Engineering (Energy and Utilities)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 07:04
1
This post received KUDOS
1
This post was BOOKMARKED
The answer of this Question is quite simple. Although you have to check for a lot of numbers to be sure In the first part minimum no. of matches can be 14 ( 6+6+2 ) so from 14 move upwards and see square if which number has 3 consecutive numbers .. you will reach 324 at 18 and voila the order of consecutive numbers is BAC same as 324 ! nailed it after that move forward to square out all other options you have to go only till 31 ! and Than less that fifty and consecutive prime? and we already know the answer as 18 so breeak it down 6+6+4 4 = 1 + 3 and 1+3 = 4 = 2^2 Bingo ! and Do give kudos if it helps



Director
Joined: 22 Mar 2011
Posts: 607
WE: Science (Education)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 07:16
1
This post received KUDOS
mandyrhtdm wrote: The answer of this Question is quite simple. Although you have to check for a lot of numbers to be sure In the first part minimum no. of matches can be 14 ( 6+6+2 ) so from 14 move upwards and see square if which number has 3 consecutive numbers .. you will reach 324 at 18 and voila the order of consecutive numbers is BAC same as 324 ! nailed it after that move forward to square out all other options you have to go only till 31 ! and Than less that fifty and consecutive prime? and we already know the answer as 18 so breeak it down 6+6+4 4 = 1 + 3 and 1+3 = 4 = 2^2 Bingo ! and Do give kudos if it helps Is your answer B? It is not correct. I didn't understand your reasoning for (2). And what do you mean by we already know the answer? Can you do fewer testings for (1)? Any conclusion about the digits or at least one of them that can help?
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Manager
Joined: 05 Jul 2012
Posts: 74
Location: India
Concentration: Finance, Strategy
GMAT Date: 09302012
GPA: 3.08
WE: Engineering (Energy and Utilities)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 07:37
EvaJager wrote: mandyrhtdm wrote: The answer of this Question is quite simple. Although you have to check for a lot of numbers to be sure In the first part minimum no. of matches can be 14 ( 6+6+2 ) so from 14 move upwards and see square if which number has 3 consecutive numbers .. you will reach 324 at 18 and voila the order of consecutive numbers is BAC same as 324 ! nailed it after that move forward to square out all other options you have to go only till 31 ! and Than less that fifty and consecutive prime? and we already know the answer as 18 so breeak it down 6+6+4 4 = 1 + 3 and 1+3 = 4 = 2^2 Bingo ! and Do give kudos if it helps Is your answer B? It is not correct. I didn't understand your reasoning for (2). And what do you mean by we already know the answer? Can you do fewer testings for (1)? Any conclusion about the digits or at least one of them that can help? Nopes the answer is D if you had gone thoroughly through t he explanations you would have found that both statements give the same result. See i will explain again : 2 says that total number of sets is less than 50 and that the sum of games one by X & Y is a whole square. let x and y be the number of games won by both and we know that to win some one must have one two more consecutive games ? so we have x + y = z^2 ( statement 2) & xy = 2 ( Passage) now all you have to determine that these two equations do have a solution. that is it! as i had solved it using the first statement already so i know the total number of games is 18 ( all three sets ) and therefore games played in the last set = 1866 = 4 and 1 & 3 is the correct value of games already known i just check if i get the same values from statement two.



Director
Joined: 22 Mar 2011
Posts: 607
WE: Science (Education)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 08:34
mandyrhtdm wrote: EvaJager wrote: mandyrhtdm wrote: The answer of this Question is quite simple. Although you have to check for a lot of numbers to be sure In the first part minimum no. of matches can be 14 ( 6+6+2 ) so from 14 move upwards and see square if which number has 3 consecutive numbers .. you will reach 324 at 18 and voila the order of consecutive numbers is BAC same as 324 ! nailed it after that move forward to square out all other options you have to go only till 31 ! and Than less that fifty and consecutive prime? and we already know the answer as 18 so breeak it down 6+6+4 4 = 1 + 3 and 1+3 = 4 = 2^2 Bingo ! and Do give kudos if it helps Is your answer B? It is not correct. I didn't understand your reasoning for (2). And what do you mean by we already know the answer? Can you do fewer testings for (1)? Any conclusion about the digits or at least one of them that can help? Nopes the answer is D if you had gone thoroughly through t he explanations you would have found that both statements give the same result. See i will explain again : 2 says that total number of sets is less than 50 and that the sum of games one by X & Y is a whole square. let x and y be the number of games won by both and we know that to win some one must have one two more consecutive games ? so we have x + y = z^2 ( statement 2) & xy = 2 ( Passage) now all you have to determine that these two equations do have a solution. that is it! as i had solved it using the first statement already so i know the total number of games is 18 ( all three sets ) and therefore games played in the last set = 1866 = 4 and 1 & 3 is the correct value of games already known i just check if i get the same values from statement two. (2) states "Each played less than 50 games", it doesn't say the sum of the games is less than 50. And not sets, but games. When dealing with DS questions, you have to work out the answer solely based on the question stem and the info in a specific statement when considering it alone. I think you mix up sets with games. It is about the third set, and the number of games each played. How are 1 and 3 relevant?
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Intern
Joined: 13 Jul 2012
Posts: 20

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 09:25
for the second part: as the number of games played is less then 50 and it states that we r looking for consecutive prime nos whose sum is a perfect square . So u start from 11 and 13 as these r the only consecutive prime no after 6. But as they sum up to 24 which is not a perfect square so this cannot be the ans.U move in this manner and u will get that only 19 and 17 as consecutive prime numbers that sum to a perfect square..



Director
Joined: 22 Mar 2011
Posts: 607
WE: Science (Education)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 09:33
invinciblelad24 wrote: for the second part: as the number of games played is less then 50 and it states that we r looking for consecutive prime nos whose sum is a perfect square . So u start from 11 and 13 as these r the only consecutive prime no after 6. But as they sum up to 24 which is not a perfect square so this cannot be the ans.U move in this manner and u will get that only 19 and 17 as consecutive prime numbers that sum to a perfect square.. Yes, that's correct. Just as a curiosity, another pair of consecutive primes whose sum is a perfect square is 71 and 73, sum being \(144 = 12^2\). The longest set in the history of tennis was 70:68 at Wimbledon last year between Isner and Mahut. But this is a topic for another forum. What about statement (1)? Do you have any idea for a shortcut?
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Intern
Joined: 13 Jul 2012
Posts: 20

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 09:44
EvaJager wrote: invinciblelad24 wrote: for the second part: as the number of games played is less then 50 and it states that we r looking for consecutive prime nos whose sum is a perfect square . So u start from 11 and 13 as these r the only consecutive prime no after 6. But as they sum up to 24 which is not a perfect square so this cannot be the ans.U move in this manner and u will get that only 19 and 17 as consecutive prime numbers that sum to a perfect square.. Yes, that's correct. Just as a curiosity, another pair of consecutive primes whose sum is a perfect square is 71 and 73, sum being \(144 = 12^2\). The longest set in the history of tennis was 70:68 at Wimbledon last year between Isner and Mahut. But this is a topic for another forum. What about statement (1)? Do you have any idea for a shortcut? As far as 71 and 73 go,The numbers wont be applicable for this question as the number of games played is less then 50. And for statement 1 my way is same as the one mentioned above. I dont think theres any shortcut for it. Hope this cud help ..



Director
Joined: 22 Mar 2011
Posts: 607
WE: Science (Education)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
Updated on: 06 Aug 2012, 13:19
1
This post received KUDOS
invinciblelad24 wrote: EvaJager wrote: invinciblelad24 wrote: for the second part: as the number of games played is less then 50 and it states that we r looking for consecutive prime nos whose sum is a perfect square . So u start from 11 and 13 as these r the only consecutive prime no after 6. But as they sum up to 24 which is not a perfect square so this cannot be the ans.U move in this manner and u will get that only 19 and 17 as consecutive prime numbers that sum to a perfect square.. Yes, that's correct. Just as a curiosity, another pair of consecutive primes whose sum is a perfect square is 71 and 73, sum being \(144 = 12^2\). The longest set in the history of tennis was 70:68 at Wimbledon last year between Isner and Mahut. But this is a topic for another forum. What about statement (1)? Do you have any idea for a shortcut? As far as 71 and 73 go,The numbers wont be applicable for this question as the number of games played is less then 50. And for statement 1 my way is same as the one mentioned above. I dont think theres any shortcut for it. Hope this cud help .. I mentioned 71 and 73 as a curiosity, not as a possible answer for the present question. Re statement (1): since A, B, C are consecutive digits, their sum is 3B, which means the number BAC is a multiple of 3. Being a perfect square, then it must be divisible by 9, therefore B itself must be a multiple of 3. The only choices are B=3 and B=6 (B cannot 0 and cannot be 9, otherwise C would be 10, not a digit). 324 is a perfect square, but 657 cannot be, as no perfect square ends in 7. This is shorter than going through all the possibilities for BAC. Oh, and (1) obviously sufficient. \(324 = 18^2\), so the score was 19:17.
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.
Originally posted by EvaJager on 06 Aug 2012, 10:07.
Last edited by EvaJager on 06 Aug 2012, 13:19, edited 1 time in total.



Manager
Joined: 05 Jul 2012
Posts: 74
Location: India
Concentration: Finance, Strategy
GMAT Date: 09302012
GPA: 3.08
WE: Engineering (Energy and Utilities)

Re: No wonder Federer lost in his Olympic tennis final, he previ [#permalink]
Show Tags
06 Aug 2012, 12:15
(2) states "Each played less than 50 games", it doesn't say the sum of the games is less than 50. And not sets, but games. When dealing with DS questions, you have to work out the answer solely based on the question stem and the info in a specific statement when considering it alone. I think you mix up sets with games. It is about the third set, and the number of games each played. How are 1 and 3 relevant?[/quote] No Dear I Haven't Mixed up ! Not at all If each played less than 50 games then out of those 50 lets say federer one x and the other guy one y, then will the sum of x & y be less than 50 or not ? and in the last set the winner won exactly two consecutive games more than the loser ! ans their sum has to be a perfect square !. Now if by solving the first statement i know the values i can just check it in the second statement and find if i can get the anwser or not ! Because you are forgetting the fact that both statements have to give the same answer ! i can either solve the second statement and waste time or i can use the answer i got already and test it in it. because if at all second statement is sufficient than it will give the same answer . now that is a FACT ! and it does By mistake i did use games ans sets interchangeably that was understandble



Intern
Joined: 05 Jun 2012
Posts: 37

Re: No wonder Federer lost in his Olympic tennis final, he [#permalink]
Show Tags
13 Aug 2012, 12:07
Start with Stmnt:b (7,9) and (17,19) are the two pairs below 50 each satisfies the condition. Putting the value of stmn b in A: from (17,19) pair we get 324 i.e. BAC , where A,B,c are consecutive integers. So , guyz please specify answer is A or C



Director
Joined: 22 Mar 2011
Posts: 607
WE: Science (Education)

Re: No wonder Federer lost in his Olympic tennis final, he [#permalink]
Show Tags
13 Aug 2012, 12:22
soumyaranjandash wrote: Start with Stmnt:b (7,9) and (17,19) are the two pairs below 50 each satisfies the condition. Putting the value of stmn b in A: from (17,19) pair we get 324 i.e. BAC , where A,B,c are consecutive integers. So , guyz please specify answer is A or C 9 is not prime. The answer is D.
_________________
PhD in Applied Mathematics Love GMAT Quant questions and running.



Intern
Joined: 25 Jun 2013
Posts: 12

Re: No wonder Federer lost in his Olympic tennis final, he [#permalink]
Show Tags
24 Jul 2013, 00:56
Quote: (1) The square of the average number of games won by Federer and Del Potro is a three digit number of the form BAC, where A,B, and C are nonzero consecutive digits. lets assume that Federer won "a" games and Del potro "b" So here statement 1 says ((a+b)/2)^2 = BAC where ABC are consecutive. lets assume (a+b)/2 = x x^2 = BAC the minimum no. of games that would have been played is 14(federer 8 and del potro 6) for federer to win the game Therefore start the value of x from 7(average of 8 and 6) By trail and error we find x = 18 therefore (a+b)/2 = 18 and also a=b+2(to win, the difference should be 2 games) Solving this we get a=19 and b=17



NonHuman User
Joined: 09 Sep 2013
Posts: 6653

Re: No wonder Federer lost in his Olympic tennis final, he [#permalink]
Show Tags
06 Dec 2017, 06:39
Hello from the GMAT Club BumpBot! Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up  doing my job. I think you may find it valuable (esp those replies with Kudos). Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
GMAT Books  GMAT Club Tests  Best Prices on GMAT Courses  GMAT Mobile App  Math Resources  Verbal Resources




Re: No wonder Federer lost in his Olympic tennis final, he
[#permalink]
06 Dec 2017, 06:39






