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DailyDays
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I12-07 16 May 2025, 03:26
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Hi everyone, do you have any similar questions to test this knowledge? It'd be much appreciated!
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Bunuel
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I12-07 16 May 2025, 11:40
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DailyDays
Hi everyone, do you have any similar questions to test this knowledge? It'd be much appreciated!
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Check these PS questions:
https://gmatclub.com/forum/the-average- ... 73362.html
https://gmatclub.com/forum/the-range-of ... 29434.html
https://gmatclub.com/forum/the-average- ... 14554.html
https://gmatclub.com/forum/set-x-consis ... 05656.html
https://gmatclub.com/forum/three-pieces ... 35503.html
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I12-07 17 May 2025, 18:49
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This is a great question that’s helpful for learning.
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MrinmoyNegel
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I12-07 27 Jun 2025, 02:27
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I like the solution - it’s helpful. Good question and explanation
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I12-07 03 Jul 2025, 07:01
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I like the solution - it’s helpful. Simple, effective and useful!
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I12-07 04 Aug 2025, 01:53
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I did not quite understand the solution. The qs is asking about the new range. Shouldn't the number of students now be 21 instead of 20 here and then we proceed with the calculation
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Bunuel
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I12-07 04 Aug 2025, 02:19
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ghost0
I did not quite understand the solution. The qs is asking about the new range. Shouldn't the number of students now be 21 instead of 20 here and then we proceed with the calculation
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The number of students is 21, yes, but the solution is correctly using only the original 20 students to calculate the initial distribution (min and max) before adding the new student. Then it adds the new student (who weighs 61 kg) to compute the new range. So the logic is correct. Please review the solution and the discission once more.
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I12-07 16 Aug 2025, 15:46
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I like the solution - it’s helpful.
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1UPantyhose
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I12-07 17 Aug 2025, 09:50
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I like the solution - it’s helpful.
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dishantkamboj123
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I12-07 01 Sep 2025, 13:25
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I don’t quite agree with the solution. Wasn't the solution required for the new class with 41 strentgh.
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Bunuel
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I12-07 01 Sep 2025, 13:29
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dishantkamboj123
I don’t quite agree with the solution. Wasn't the solution required for the new class with 41 strentgh.
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This is a hard question and it’s okay if you don’t get it the first time. That’s why it’s important to review the solution carefully.

The range being asked about is for the new class of 21 students (after the extra student joined). The old 20-student setup is only used to figure out the possible distribution of weights, which then determines how the new student’s 61 kg weight changes the extremes. So yes, the official solution is already solving for the 21-student class, not just the original 20.
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I12-07 25 Sep 2025, 11:37
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I like the solution - it’s helpful.
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I12-07 27 Sep 2025, 07:01
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Why we are not doing naything with the highest weight person? Why are we only concerned with max and min the lowest weight student ? The range can be affected by both low and high
Bunuel

To maximize the range — we want the smallest possible minimum weight. That happens when 1 student is very light (x kg) and the other 19 students are as heavy as possible (x + 10 kg), while still maintaining the total weight.

To minimize the range — we want the largest possible minimum weight. That happens when 19 students are as heavy as possible (x kg), and only 1 student is lighter (x + 10 kg), again keeping the total weight fixed.

For more details, please review the discussion above.
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I12-07 27 Sep 2025, 11:40
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mkeshri185
Why we are not doing naything with the highest weight person? Why are we only concerned with max and min the lowest weight student ? The range can be affected by both low and high

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The highest weight is already tied to the lowest weight because the difference between them is fixed at 10. So once you decide the lowest possible weight, the highest is automatically determined as lowest + 10. That is why the solution only varies the minimum weight, adjusting that also adjusts the maximum weight at the same time, and the range follows directly.
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I12-07 30 Sep 2025, 07:01
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I like the solution - it’s helpful.
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I12-07 30 Sep 2025, 16:31
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I12-07 28 Oct 2025, 09:05
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I like the solution - it’s helpful.
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I12-07 29 Oct 2025, 06:37
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I did not quite understand the solution. I did not get how the remaining students were taken as x+10, can someone explain this in detail.
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I12-07 29 Oct 2025, 06:44
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quialias
I did not quite understand the solution. I did not get how the remaining students were taken as x+10, can someone explain this in detail.
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Try alternative solutions here: https://gmatclub.com/forum/in-a-class-o ... 23266.html Hope it helps.
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I12-07 15 Nov 2025, 02:24
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I like the solution - it’s helpful.
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