GMAT Club World Cup 2022 (DAY 9): There are several renowned Athletics

the manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving, but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club. Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.
Implies
more number of sprinters joined and their average speed is higher than the present sprinters of the club


Which of the following statements most strongly strengthens the above conclusion?

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city. not relevant
B. This year many athletes leaving Acerunners retired from Athletics permanently. not relevant
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville. comparison is with sprinters of Acerunners in the past and present after the changeove. hence incorrect
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners. Since the weakest sprinters have left and the sprinters with high average speed joined,,, this statement most strongly strengthens the conclusion. Correct
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year. Marathon runners average speed is not being considered. Irrelevant
Answer D

What do we know? - The premise:
> There are several renowned Athletics clubs in the city of Sportsville.
> It is a common practice in Sportsville that the athletes change clubs frequently, some every year.
> This year several sprinters have left the club Acerunners.
> However the manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving,
> but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club.

What has the author concluded? - The conclusion:
it can be concluded that the average speed of the sprinters at Acerunners has risen this year

What is the logical jump? - The assumption:
The outgoing athletes' average speed was lower than the average speed of the incoming ones.

Let's analyse the options:



Irrelevant. Why do we care about the sprinters of the adjacent city?



This won't help us conclude that the average speed of the club has risen this year. Hence, incorrect



This can happen if the outgoing sprinters retired or if the outgoing sprinters joined an underdog club which has sprinters with very low average speeds. We can't conclude anything about Acerunners' average speed this year.



Okay so the outgoing sprinters were slower than the ones who stayed. (A < B)
And the ones who stayed are slower than the incoming sprinters (B < C)
Therefore, we can conclude that A < C.
And thus, we can safely say that the average speed has risen this year.



We are concerned about the average speed here. Individual speeds won't help our case.


Hence, option D is the correct answer.

Premise :
There are several renowned Athletics clubs in the city of Sportsville. It is a common practice in Sportsville that the athletes change clubs frequently, some every year. This year several sprinters have left the club Acerunners

IC :
The manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving, but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club

Conclusion :
Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city. irrelevant
B. This year many athletes leaving Acerunners retired from Athletics permanently. irrelevant
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville. no information about sprinter speed comparison
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners. this is valid and does strengthens the conclusion , if more sprinters left who were slow and more than those who left have joined and there avg speed is high then this supports the conclusion
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year. sprinters club it is not marathon runners

OPTION D is correct

Statement, which support the possibility that sprinters who left Acerunners had an average sped less than or equal to the rest of the sprinter at Acerunners, will strongly strengthens the above conclusion

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city: Irrelevant. Reject
B. This year many athletes leaving Acerunners retired from Athletics permanently: Irrelevant. Reject
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville: Irrelevant. Reject
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners: Support the conclusion. Correct answer
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year: It's weakening the conclusion. Reject

IMO D


A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city. - ADjacent city's data is irrelevant
B. This year many athletes leaving Acerunners retired from Athletics permanently. - irrelevant
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville. -- why do we bother about other clubs
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners. - Correct those who left were slower than those who currently are there plus the new sprinters who joined also have a higher average so definitely the overall average will get a boost.
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year. - what about other sprinters who are not marathon runners. Of all the sprinters in this option we are focussing on the one section only.

Answer is D
A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city. Irrelevant
B. This year many athletes leaving Acerunners retired from Athletics permanently.Irrelevant
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville. Irrelevant
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners. Correct. This strengthens the conclusion
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year. Irrelevant

Premise:
1. Several sprinters have left the club Acerunners.
2. the number of sprinters joining the club this year higher than those leaving,
3. the average speed of the athletes who joined higher than the average speed of all the sprinters of the club.

Conclusion: Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.

To find the statement that most strongly strengthens the above conclusion.
Analysis: The argument will be strengthened if the speed of runners who left the club was lower than the avg speed of the club.

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city.
--> Incorrect: Irrelevant, as the conclusion only argues about avg speed of sprinters in Acerunners, a club in Sportsville.

B. This year many athletes leaving Acerunners retired from Athletics permanently.
--> Incorrect: It is still possible that the sprinters who left or retired from the club had so high average speed that even with addition of new team members the average did not rise.

C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.
--> Incorrect: It is still possible that the sprinters who left from the club had so high average speed that even with addition of new team members the average did not rise.

D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners.
--> Correct: It is still possible that the sprinters who left or retired from the club had so high average speed that even with addition of new team members the average did not rise.

E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.
--> Incorrect: This statement claims about only few new marathon runners. Also, if the avg speed of runners who left the club was very high then addition of these new runners might not be sufficient to increase the avg speed of the club.

heh, "most strongly strengthens".

I don't love the wording of this problem. There's enough context here—especially with that "also", there (boldfaced)—to determine that this and this are two references to the same group of athletes. By using two different wordings for the same specific group, though, this problem violates GMAC's own conventions for CR problem writing. Not good. (When GMAC includes two references to the same specific detail in a CR problem, they're scrupulous about using the same words both times.)


In problems like this one—basically, statistics problems couched in very wordy words—it's alws a good idea to extract the statistical findings from the paragraph in order to consider them more easily.

The statistical findings here are:
• Some sprinters left the club. Some others joined—more than the # who left.
• The NEW (just joined) sprinters are FASTER than the club average. <— Isolating this fact makes it VERY plain that we DON'T yet have the corresponding fact about the group who left!

Well yeah... let's go to the choices and look for that OTHER corresponding fact we want—Were the sprinters who LEFT the club SLOWER than average?

D says exactly this. Answer is D. Done and dusted.


.

BTW
This problem really needs work... There's also a second violation of GMAC's best practices here, in that the correct answer actually completes a rigorous PROOF of the given conclusion.
That contradicts the wording of the question ("most strongly..."). GMAC doesn't write sloppy problems like this; if a problem's conclusion is rigorously proved, there will not be any hedging language like "best" or "most strongly" that's only sensible in arguments whose conclusion is NOT rigorously proved.

There are several renowned Athletics clubs in the city of Sportsville. It is a common practice in Sportsville that the athletes change clubs frequently, some every year. This year several sprinters have left the club Acerunners. However the manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving, but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club. Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.

Which of the following statements most strongly strengthens the above conclusion?

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city.
Claim is related to club acerunner and not Sportsville city.
B. This year many athletes leaving Acerunners retired from Athletics permanently.
Whether the retire ones are sprinter or not? Also if the retired ones are sprinter with high speeds than it will weaken the conclusion.
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.
It may be due to other clubs average speed of sprinters has come down, hence the acerunners has highest average among all the clubs without an increase in average speed.
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners.
Sprinter who left were slower, sprinter who joins has speed higher than the average speed. Thus resultant average speed will be increased. Suppose for 3 sprinter having speed 10mph,20mph,30mph average is 20mph. If in place of 10mph a new sprinter of 13mph joins, so the new average will be 21mph. Increase in average speed by 1mph.
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.
Conclusion is based on sprinter and not on marathon runners.

Hence D.

There are several renowned Athletics clubs in the city of Sportsville.
It is a common practice in Sportsville that the athletes change clubs frequently, some every year.
This year several sprinters have left the club Acerunners.
However the manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving, but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club.

Conclusion: - Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.

Which of the following statements most strongly strengthens the above conclusion?



We are NOT concerned with sprinters in adjacent city
Incorrect


The average speed of the sprinters at Acerunners will rise this year, if average speed of sprinters joining will be more than the average speed of sprinters retiring. It does not matter whether they retire permanently or not.
Incorrect


We are NOT concerned with all the clubs in Sportsville.
Incorrect


The average speed of the sprinters at Acerunners will rise this year, if average speed of sprinters joining will be more than the average speed of sprinters retiring. It is already mentioned that the average speed of the athletes who joined was higher than the average speed of all the sprinters of the club. If sprinters who left Acerunners were on an average slower than the sprinters of Acerunners, then average speed of sprinters will rise this year.
Correct


We are NOT concerned with marathon runners.
Incorrect

IMO D

We are not concerned about the comparison between average speed of sprinters in Sportsville and that in the adjacent city. A is out.
It does not matter whether athletes who left Acerunners retired permanently or joined some other company. B is out.
We don't want to compare the average speed of sprinters at Acerunners with other clubs in Sportsville. C is out.
E talks about marathon runners but the argument is concerned with sprinters. Hence, E is out.

If the sprinters who left Acerunners were on an average slower than the sprinters of Acerunners and the new sprinters who joined Acerunners this year were on an average faster than the sprinters of Acerunners, the average speed of all the sprinters at Acerunners will definitely increase this year from the last year. Hence, answer is D.

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city.
The comparison with adjacent city runners is irrelevant
B. This year many athletes leaving Acerunners retired from Athletics permanently.
the retirement is irrelevant to the question of higher speed of actual club
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.
irrelevant comparison with all runners of the city
D. The sprinters who left Acerunners were on average slower than the sprinters of Acerunners.
This is the correct answer, if we replace a selection of runners that have an average speed lower than that of another selection of runners, then the global average speed of the club will be higher , no doubt,
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.
irrelevant comparison with all marathonrunners of the city

ANSWER D

Why?

Which of the following statements most strongly strengthens the above conclusion? => we must find the answer that supports the conclusion.

- Conclusion : Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.
- Premise 1: the number of sprinters joining the club this year higher than those leaving and the average speed of the athletes who joined higher than the average speed of all the sprinters of the club

Premise 2 (guessing) : for the conclusion to be true we need to have something that prove that the average speed of sprinter joining this year is higher or equal to the average of those who left the club or we must prove that those leaving where the slowest or something like that.




A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city. IRRELEVANT

B. This year many athletes leaving Acerunners retired from Athletics permanently.
IRRELEVANT

C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.=>
it's a try but we have no clue about the speed of those leaving so it's a bit poor. We SKIP THIS ANSWER

D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners.
EXACTLY WHAT WE ARE LOOKING FOR. THIS IS OUR WINNER.

E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year. => marathon? Seems like we are off topic here. IRRELEVANT

Posted from my mobile device

Conclusion: "The average speed of the sprinters at Acerunners has risen this year."

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city.
INCORRECT. Whether the average speed of sprinters in Sportsville is lower than those of adjacent cities is irrelevant to the argument.

B. This year many athletes leaving Acerunners retired from Athletics permanently.
INCORRECT. Again whether many athletes leaving Acerunners retired from athletics permanently is irrelevant to the argument.

C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.
INCORRECT. Even, if the average speed of all sprinters at Acerunners this year is the highest among all the clubs in Sportsville, it could still be higher or lower or equal to the average speed of the sprinters at Acerunners last year.

D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners.
CORRECT. If the average speed of the sprinters who left Acerunners this year was lower that the average speed of all sprinters in Acerunners in addition to the fact that the average speed of the new sprinters who joined this year is more that average speed of all sprinters fills the gap between the premise and conclusion, and thus support the argument. Notice we can surely say the average speed of sprinters in Acerunners increased this year only by knowing both these facts.

E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.
INCORRECT. This may be the case but even with addition of 'some' runners having average speed higher than that of all marathon runners of Acerunners, there could be others who joined Acerunners this year and have such low average speed such that average speed of all runners in Acerunners this year is lower than that of last year.

IMO, Option D is the answer. This question is like an Arithmetic problem.

Assume five sprinters with speeds of 10,11,12,13,14 meters per second were originally in the team. The average speed is 12 meters per second.

The two lowest speeds of 10 and 11 meters per second left the team. The average speed is now 13 meters per second.

4 new sprinters joined the team. Their speeds are 15,16,17 and 18 meters per second.

The speeds of new team is now 12,13,14,15,16,17 and 18 meters per second. The average speed in now 15 meters per second.

IMO, Option D most strongly strengthens the conclusion in the question.

[quote="Bunuel"]There are several renowned Athletics clubs in the city of Sportsville. It is a common practice in Sportsville that the athletes change clubs frequently, some every year. This year several sprinters have left the club Acerunners. However the manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving, but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club. Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.

Which of the following statements most strongly strengthens the above conclusion?

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city.
-This is incorrect.Even if the average speed of the sprinters in Sportsville is lower than adjacent city that does not prove that the average speed of the sprinters at Acerunner will go high
B. This year many athletes leaving Acerunners retired from Athletics permanently.
This is out of scope.This statement does add any value to the argument
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.
This is incorrect.The average speed of all the sprinters at Acerunners can be highest but that does not justify the point that the average speed of the sprinters at acerunners will rise this year
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners.
This is the correct option.As the sprints who left Acerunners were on an average slower than the sprinters of Acerunners and the sprinters who joined Acerunners have highest average speed than the existing sprinters thus the average speed of sprinters will rise high this year
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.this is out of scope because here we are talking about the average speed of the sprinters not the marathon runners

[quote="Bunuel"]There are several renowned Athletics clubs in the city of Sportsville. It is a common practice in Sportsville that the athletes change clubs frequently, some every year. This year several sprinters have left the club Acerunners. However the manager of Acerunners claims that not only is the number of sprinters joining the club this year higher than those leaving, but also is the average speed of the athletes who joined higher than the average speed of all the sprinters of the club. Therefore it can be concluded that the average speed of the sprinters at Acerunners has risen this year.

Which of the following statements most strongly strengthens the above conclusion?

A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city.
B. This year many athletes leaving Acerunners retired from Athletics permanently.
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville.
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners.
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.

This question was provided by GMAT Club for the GMAT Club World Cup Competition Compete, Get Better, Win prizes and more

 

Some sprinters left club. Club says that avg speed of those who joined is higher than that of club. So avg speed of club has risen.

we need a strengthener.
A. The average speed of the sprinters in Sportsville is lower than those of the adjacent city. - Adjacent city is OUT OF SCOPE - INCORRECT
B. This year many athletes leaving Acerunners retired from Athletics permanently. - But may be their avg speed was higher than avg speed of those who joined. If so avg speed will be lower than before - INCORRECT
C. The average speed of all the sprinters at Acerunners this year is the highest among all the clubs in Sportsville. - But what if it was highest among all clubs before. Then inspite of this avg speed of club can be lower than last year -- INCORRECT
D. The sprinters who left Acerunners were on an average slower than the sprinters of Acerunners. -- If avg of those leaving is lower than avg of club that means avg has increased. -- CORRECT
E. Some new marathon runners whose average speed is higher than that of all the marathon runners of Acerunners joined the club this year.- But that may not help to increase the avg of club. What if the rest who joined has very low speed. Then avg of club will be reduced. --- INCORRECT