For a certain radio station in India, the table shows the songs ranked

Question

For a certain radio station in India, the table shows the songs ranked among the top 10 during Week W. The rankings are determined by the number of listener requests for each song, with rank 1 being the most requested, rank 2 the second-most requested, and so on. Lesser numbers constitute higher rankings. The table also gives, as of Week W, each song's rank for the previous week, the number of weeks it has been among the top 20, and its peak rank (the highest ranking it has achieved). In the column for Previous week's rank, "n/a" indicates that the song was not ranked in the week immediately prior to Week W.

Week W
rank  
  Song  
  Previous week's
rank  
  Weeks in
top 20  
  Peak
rank  
 
   1  
 A 
 1 
 4 
 1 
 
   2  
 B 
 2 
 10 
 1 
 
   3  
 C 
 6 
 3 
 3 
 
   4  
 D 
 4 
 6 
 4 
 
   5  
 E 
 3 
 11 
 1 
 
   6  
 F 
 n/a 
 1 
 6 
 
   7  
 G 
 5 
 9 
 3 
 
   8  
 H 
 10 
 3 
 8 
 
   9  
 I 
 12 
 5 
 9 
 
   10  
 J 
 13 
 2 
 10

For each of the following questions, select  Can be answered  if that question can be answered using only the information in the table. Otherwise, select  Cannot be answered .

egmat · Accepted Answer

The dataset for this TA question is simple – very typical relatable context. But yet it is a difficult question because of small traps that happen if one does not draw pertinent inferences while ‘owning the dataset’.

Watch the solution and observe the following:

https://www.youtube.com/watch?v=_NjxemqUD5o

Observe how answering some of these questions will help you answer the question correctly.  
 
 What does peak rank mean? 
 What does N/A mean in terms of ranking in the previous week?

Observe the approach for the three statements.  
 
 To answer each statement, we first determined exactly how we are going to process the data in the table. Then we went to the table. Looking at the table without having a concrete approach is detrimental. 
 For statements 1 and 2, we did not really find the number. We just found whether we can find the number or not. 
 For statement 3, it was important for us to understand the data that WAS NOT available for the previous week.

If you answered this question incorrectly, then it will be because of the failure to do one or more of the above. Determine that behavioral reason and enter that in your error log.

chetan2u · Answer

How many of the top 5 songs for Week W had a higher rank for Week W than they did for the previous week?
Arrange week W in ascending order of standings, that is 1,2,3,4,5. You will surely get ranking for the previous rank in front of each song. Question  can be answered  from Data. 
 
How many of the top 10 songs for Week W were not among the top 10 in the previous week?
Again we have exact 10 songs and their rankings of the previous week can be seen and question  can be answered .

How many of the top 10 songs for the week immediately prior to Week W have ever been at ranking 1?
Although we have peak rankings for each of the top 10 song for week W, the same can not be said of week prior to week W. 
Songs that were 7, 8 and 9 in week prior do not have a place in week W and so data is not available for these songs. 
 Cannot be answered.

Priyam8 · Answer

Why can’t the 3 question be answered? Can’t we see the previous week’s ranks of songs and the peak ranks ?

Posted from my mobile device

Abhishek009 · Answer

Check Previous week's rank , it includes , 12 & 13 excludes 7, 8 & 9 and we can not comment on those...

anikpait17 · Answer

for the 3rd question: I think it says songs that has been "ever been ranking 1" that we dont know if the songs has been ever been ranked 1 before previous week or it is the first time that the song is ranked 1, please correct me if m wrong.

GMACOG · Answer

Hello  anikpait17 
I think you have misunderstood the argument.

The "peak ranking" column indicates whether that particular song was EVER on rank 1. However, the ans to this will be  can NOT be answered   simply because not all the top 10 ranks for the week immediately prior to week W has been given to us.
Missing ranks : 7,8,and 9.

I hope this answers your doubt.

JJ.jj · Answer

But the previous week's rank only has 1 in rank 1. Shouldn't the answer always be 1?

KarishmaB · Answer

We have this week's rank, last week's rank, best rank till date and number of week in rankings.

How many of the top 5 songs for Week W had a higher rank for Week W than they did for the previous week?

I have this week's 5 top ranks and  their previous week's ranks. I can determine this. Do I need to? No. But I can. 
Among top 5, only song C has a higher rank this week compared to last week. (just to give clarity)

How many of the top 10 songs for Week W were not among the top 10 in the previous week?

I have this week's 10 ranks and their previous week's ranks. I can determine how many of them were not in top 10 last week. Do I need to? No. But I can. 
F, I and J were not among the top 10 previous week. (just to give clarity)

How many of the top 10 songs for the week immediately prior to Week W have ever been at ranking 1?

In the previous week's ranks, ranks 7, 8 and 9 are missing. We don't know which songs had those ranks last week. So of course I do not have their data of best ranks obtained. Hence, I cannot determine this.

ANSWER:
Can be answered
Can be answered
Cannot be answered

Gemmie · Answer

How many of the top 5 songs for Week W had a higher rank for Week W than they did for the previous week? => Can be answered

We know all the previous week ranking of the top 5 songs of week W

How many of the top 10 songs for Week W were not among the top 10 in the previous week? => Can be answered

We know all the previous week ranking of the top 10 songs of week W

How many of the top 10 songs for the week immediately prior to Week W have ever been at ranking 1? => Cannot be answered

We do not know all the top 10 songs in the week previous to week W (the 7th, 8th and 9th are unknown)

Ankit__7182 · Answer

Can you please help clarify N/A here. I got middle question wrong here. Doubtful of your explanations as below:

KarishmaB 
How many of the top 10 songs for Week W were not among the top 10 in the previous week?
 
->I still think it cannot be answered due to F being N/A. It is like assuming that F's previous week's ranks was not among 10 whereas in really it cannot be determined.
Let us say if question was exact opposite- How many of the top 10 songs for Week W were not among the top 10 in the previous week?
what would your answer be- 7 right ?. Here we are not including N/A but in original question we are though Question is asking very specific case on number line. I think due to N/A we cannot answer this question.

egmat  I think you have wrongly mentioned in video Time stamp (10:10)
that N/A was all those that were> 20  (where is that mentioned ???)  in previous week so automatically it is >10.

chetan2u · Answer

The answer lies in the statement: 
 In the column for Previous week's rank, "n/a" indicates that the song was not ranked in the week immediately prior to Week W.

Now we know F was in top 20 once(It is given in the column. )
However, previous week it was n/a, since it was not in top 20. (Exactly what the bold portion means.)

Ankit__7182 · Answer

Hi  chetan2u , Thanks for prompt response

Now we know F was in top 20 once (It is given in the column. ) ->  Agree . and that once is also current week only right!

However, previous week it was n/a, since it was not in top 20. (Exactly what the bold portion means.) ->  Not agree. 
Going by your logic, at least there should be a number given to it, greater than 20, in previous week's rank to justify that it was not in top 20.

My logic of N/A as per given statement and table data is that it mean the song was released this week only  and it secured 6th position. This logic also satisfies other 2 columns in table. So we cannot determined and answer this.

Please Correct me if I am wrong in my logic.

KarishmaB · Answer

We are given that n/a means it was not ranked last week. So n/a does not  mean 'not available.' It means 'not applicable.'
So F is n/a means F was not in the top 10 ranks last week. Also note that for F, 'week in top 20' is 1. So only this week has F been in top 20. So last week F was not in top 20.

chetan2u · Answer

Yes, I would expect it to be mentioned that previous week rank restricts ranks to top 20. So, the wordings can be taken to suggest that the song was not listed. You are correct on that front as the wordings are ambiguous on what exactly ranking means. Is it for 20 top or each of lakhs of songs released over the years having a unique standing? Practically, it is absurd to think that all songs would be ranked but then literally going by wordings, it is open to debate.

However, it should not change the answer. Was F ranked in top 10? No, it may be because it was not listed, if that is what the words suggest.

It could be same about a new blockbuster song, say X, that is in top 10 in the very first week of release. 
Was X in top 10 last week? You would say ‘No’.

Was Mr Rahul Gandhi the Home minister at the time of Independence of India?
You may say “ What rubbish!, of course no, he was not even born then. “

Posted from my mobile device

hughng92 · Answer

I had the exact same reasoning for statements 2 and 3. However, why tripped me off was the "n/a": my interpretation for the "n/a" was that if the data is available, then how can I conclude whether a song that is ranked "X" in week W was ranked "n/a" the previous week? I was a bit confused.

illegallyblonde · Answer

Hi  anikpait17 , I selected "cannot be answered" for the same reason as yours.

Here's what we missed out on: the Peak Rank column. That shows all the times those particular songs have been at Rank 1 so yes, it could be answered IF we had the info about the missing numbers, ie 7, 8, etc.

Hope that helps!

av722 · Answer

Q1: Can be answered. 
Sort the table by week W rank. ABCDE are highest ranking songs for week w. In the previous week, only C has higher rank.

Q2: Can be answered. 
We're looking at 'Week W Rank' column and 'previous week's rank'. If the values are > 10 or 'n/a,' we know they weren't among the top 10 in the previous week.

Q3: Cannot be answered. 
We're looking at 'Previous Week's rank' and 'Peak rank'. The problem with this is that we don't receive information about the songs that rank at 7, 8, and 9 for the previous week, which is important because we need to see what the peak rank for those songs is (if they were indicated by '1,' then we would add that to our count).

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For a certain radio station in India, the table shows the songs ranked

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Can be answered	Cannot answered
		How many of the top 5 songs for Week W had a higher rank for Week W than they did for the previous week?
		How many of the top 10 songs for Week W were not among the top 10 in the previous week?
		How many of the top 10 songs for the week immediately prior to Week W have ever been at ranking 1?

GMAT Graphs and Tables (G&T) Questions

For a certain radio station in India, the table shows the songs ranked

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