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In a certain set of five numbers the median is 200
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03 Mar 2012, 11:39
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In a certain set of five numbers the median is 200. Is the range greater than 80? (1) The average (arithmetic mean) of the numbers is 240 (2) Three of the numbers in the set are equal
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Re: In a certain set of five numbers the median is 200
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03 Mar 2012, 13:56
In a certain set of five numbers the median is 200. Is the range greater than 80?Say the set is {a, b, 200, c, d}. Question: is da>80? (1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient. (2) Three of the numbers in the set are equal. Clearly insufficient. Answer: A.
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Re: In a certain set of five numbers the median is 200
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14 May 2013, 18:00
Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. why b is clearly insufficient ?



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Re: In a certain set of five numbers the median is 200
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14 May 2013, 18:32
TheNona wrote: Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. why b is clearly insufficient ? Lets say the set is a,b,200,c,d as taken by bunuel... Now we donot know anything about the mean of the numbers. If the numbers are 200,200,200,220,230 the range will be 30 If the numbers are 200,200,200,220,290 the range will be 40. and so onnnnnn.... So we cannot say desicively what the range is? Whether it is greater than 80 or not..So it is not sufficient



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Re: In a certain set of five numbers the median is 200
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Updated on: 15 May 2013, 12:08
tom09b wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
(1) The average (arithmetic mean) of the numbers is 240 (2) Three of the numbers in the set are equal From F.S 1, as the average is 240, we can assume that each of the 5 elements is 240 . However , as the median is 200, the two elements below the median can be atmost 200 each and the two elements above median can be atleast 200 each. Now,Range = Max(element)Min(element). After maximizing the 2 elements below the median, we can have the following set : 200,200,200,300,300. Now,to have a value of range=80, we would have to have the value of the Max(element) = 280. Notice : 200,200,200,320,280 > The Max(element) changes to 320 . Thus, any change on the Max(element) will ALWAYS lead to a range>80.Also, any decrease on the Min(element) will only increase the numerical value of Range above 80. Sufficient. From F.S 2, we can have either 160,180,200,200,200 where range<80 OR 100,120,200,200,200 where range>80. Insufficient. A.
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Originally posted by mau5 on 15 May 2013, 00:33.
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Re: In a certain set of five numbers the median is 200
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15 May 2013, 00:46
TheNona wrote: Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. why b is clearly insufficient ? Because it's easy to construct the sets which give two different answers to the question: {200, 200, 200, 201, 100000000} {200, 200, 200, 201, 202}
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Re: In a certain set of five numbers the median is 200
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15 Dec 2016, 15:58
This is a great Question. Excellent Solutions have been provided above. Here is my solution to this one=>
Let the 5 numbers be in increasing order as =>
a b c d e
Now #=5
Hence median = 3rd term => c So c= 200
Now we are asked if range is >80 or not. Here we will calculate the minimum value of range and if the minimum value of range >80 then range will be great than 80
Statement 1=> Mean =240
There is a very important property of mean => Sum of deviations around the mean is always zero.
Now to minimise the range => a=b=c=200
Total negative deviation occurred =120 Hence to balance out this => d and e must have a 120 positive devotion when added. To minimise range we must minimise e for that we she maximise d d=e=300
Hence minimum range = 300200=100
Hence sufficient
Statement 2> Three values are equal Notice no mean is provided. E.g=> a=e=200=> Range =0 a=200 and e=999999 => Range>80 Hence insufficient
Hence A
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Re: In a certain set of five numbers the median is 200
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16 Dec 2016, 21:12
Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. Bunuel, shouldnt it be minimize A and maximize D?



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In a certain set of five numbers the median is 200
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16 Dec 2016, 21:29
OreoShake wrote: Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. Bunuel, shouldnt it be minimize A and maximize D? Hi You see, if we minimise a and maximise d => The range would be maximum. we have to check for the minimum value of range. E.g=> Lets see an example with 3 numbers => a,b,c Median = 100 => b=100 a,100,c be the three numbers in increasing order. a=0 c=200 the range = 200
if a=100 c=100 Range =0
Hence we have to maximise a and minimise d in our original question
Regards Stone Cold
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In a certain set of five numbers the median is 200
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Updated on: 25 Aug 2019, 08:05
tom09b wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
(1) The average (arithmetic mean) of the numbers is 240 (2) Three of the numbers in the set are equal Given: In a certain set of five numbers the median is 200. Asked: Is the range greater than 80? (1) The average (arithmetic mean) of the numbers is 240 Sum of 5 numbers = 240 * 5 = 1200 For minimum range Let the numbers be {200,200,200,x,x} 2x = 600 x = 300 Minimum Range = 300200=100>80 SUFFICIENT (2) Three of the numbers in the set are equal Case 1: Let the numbers be {200,200,200,x,y} Range = y200 But value of y is not provided. Case 2: Let the numbers be {x,y,200,200,200} Range = 200x But value of x is not provided. NOT SUFFICIENT IMO A
Originally posted by Kinshook on 25 Aug 2019, 07:58.
Last edited by Kinshook on 25 Aug 2019, 08:05, edited 1 time in total.



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Re: In a certain set of five numbers the median is 200
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25 Aug 2019, 08:01
TheNona wrote: Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. why b is clearly insufficient ? TheNonaLet us consider 2 cases Case 1: {200,200,200,c,d} Since d may take any value NOT SUFFICIENT Case 2: {a, b, 200, 200, 200} Since a may take any value NOT SUFFICIENT



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Re: In a certain set of five numbers the median is 200
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25 Aug 2019, 08:03
OreoShake wrote: Bunuel wrote: In a certain set of five numbers the median is 200. Is the range greater than 80?
Say the set is {a, b, 200, c, d}. Question: is da>80?
(1) The average (arithmetic mean) of the numbers is 240 > the sum of the numbers is 240*5=1,200. Now, let's see whether the range can be less than 80, so let's try to minimize the range. The range will be minimized if we maximize a and minimize d. Maximum value of a as well as b is 200 and minimum value of d is c, so our set will be: {200, 200, 200, d, d} > 600+2d=1,200 > d=300 > the range=dc=300200=100>80. Sufficient.
(2) Three of the numbers in the set are equal. Clearly insufficient.
Answer: A. Bunuel, shouldnt it be minimize A and maximize D? OreoShakeWe have to prove than minimum possible range > 80 So that all possible ranges will be > 80 To minimise range we have to maximise a and minimise d




Re: In a certain set of five numbers the median is 200
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