The graph shows the percentage of children in particular grade levels

Question

https://gmatclub.com/forum/download/file.php?mode=view&id=60900 The graph shows the percentage of children in particular grade levels that participated in the six afterschool activities offered by a school in 2017. No child was allowed to participate in more than one sport activity (soccer, tennis, track) or more than one non-sport activity (math team, band, debate team) but children were allowed to participate in one activity from each category (sport or non-sport). Every child had to participate in at least one of the six activities. For each of the following, use the drop-down menu to create the most accurate statement on the basis of the chart: 1. If more students were in band in the 9th grade class than in the 11th grade class, then at a minimum, the number of students in the 9th grade class must be approximately GRAPH_1_PLACEHOLDER greater than the number in the 11th grade class. 2. In 2017, the GRAPH_2_PLACEHOLDER class had the smallest percentage of students who participated in two of the six activities. The last two questions based on this stem can be found here. 9.jpg

CEdward · Answer

If more students were in band in the 9th grade class than in the 11th grade class, then at a minimum, the number of students in the 9th grade class must be approximately____________greater than the number in the 11th grade class.

A. 10% 
B. 15%
C. 18%
D. 22%

In 2017, the____________class had the smallest percentage of students who participated in two of the six activities.

A. 8th grade
 B. 9th grade 
C. 10th grade
D. 12th grade

Approximately___________percent of 8th graders in 2017 participated in exactly one of the six after-school activities.

A. 5
 B. 10 
C. 15
D. 20

In 2017 there____________in which more students participated in sport activities than non-sport activities.

A. were no grade levels
B. was one grade level
 C. were two grade levels 
D. was three grade levels

Sajjad1994 · Answer

OA of this question has been updated, It is:

C, B, C and C

Thank you

LHE · Answer

Approximately___________percent of 8th graders in 2017 participated in exactly one of the six after-school activities.

How to calculate this answer?

Sajjad1994 · Answer

Official Explanation

1. If more students were in band in the 9th grade class than in the 11th grade class, then at a minimum, the number of students in the 9th grade class must be approximately____________greater than the number in the 11th grade class.

For the first prompt, you have to use the percentage data to make conclusions about the absolute number. In the 9th grade class, 55% of the students were in band, and in the 11th grade class, 65% of the students were in band. Letting x = the number of students in the 9th grade class and y = the number of students in the 11th grade class, then it must be true that 55% of x is greater than 65% of y, because the question states that more students were in the band in 9th grade than in 11th grade. As a result you have the equation .55x = .65y and x/y = .65/.55. Reducing that you know that x/y = .13/.11 and x is thus 2/11 greater than y. 1/11 can be approximated as .09 so 2/11 would be approximately .18

18% is correct.

2. In 2017, the____________class had the smallest percentage of students who participated in two of the six activities.

For the second prompt, you need to find the grade level that maximizes the number of students who participated in only one activity. In the 9th grade, it is clear that a particularly low percentage of students participated in sport activities. Adding them up, you see that it was approximately 10% for tennis, 25% for track, and 35% for soccer or 70% total. This means that the remaining 30% of students must have participated in exactly one of the non-sport activities. For non-sport activities, the sum from the graph is approximately 95%, so that means 5% had to participate in exactly one sport activity. This means that 35% of the students participated in exactly one activity so 65% participated in exactly two, the smallest percentage substantially out of all the different grades (12th grade is closest with 75% participating in exactly two).

The correct answer is 9th grade.

3. Approximately___________percent of 8th graders in 2017 participated in exactly one of the six after-school activities.

For the first prompt, you need to look at 8th grade data and add up the percentages in each of the two categories: sport and non-sport. For the three non-sport activities, there were approximately 15% on the debate team, 20% on the math team, and 55% in band, so 90% of the class participated in non-sport activities. The remaining 10% must have participated in exactly one of the sport activities because each student had to participate in at least one of the six activities (but never two or more of one type). Adding up the data for the sport activities, you see 45% played soccer, 25% played tennis, and 25% ran track. Since 95% of the class participated in sport activities, the remaining 5% must have participated in exactly one of the non-sport activities. Adding the 10% and 5%, you see that 15% participated in exactly one activity.

Correct answer is (C).

In 2017 there____________in which more students participated in sport activities than non-sport activities.

For the last prompt, you need to go through all of the data. For each grade level you need to estimate the two categories and see which one is greater. Visually, you should isolate the two different groups and look for years in which the non-sport activities were particularly low. From the first prompt, you know that 8th grade is one grade level in which more students participated in sport activities than non-sport activities (by 95% to 90%). In 7th grade, 100% of students participated in non-sport activities, so this statement is not true for that grade. 9th grade can be quickly eliminated as well, because only 70% of students participated in sport activities. In 10th and 11th grade, the data is fairly similar and in both cases more students participated in non-sport activities by a decent margin. However, in the 12th grade year it is clear from the charts that there was a substantial change: only about 80% of students participated in non-sport activities while nearly 100% participated in sport activities. As a result, the   correct answer is (C)   as there were two grade levels in which the statement is true.

wArrior902 · Answer

For second prompt, we can just sum all the percentages and whichever has the lowest sum is the answer. sport + non sport - 100 = both activities. So essentially whichever grade has lowest sum will have lowest % of students who took 2 activities.

The graph shows the percentage of children in particular grade levels

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The graph shows the percentage of children in particular grade levels

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

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745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards