range

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range

by vipulgoyal » Wed Feb 27, 2013 8:11 pm
the sum of the 10 numbers is 28, if the range of these numbers is 2, how many 3 are there

1>0
2>5
3>9
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by aditya8062 » Wed Feb 27, 2013 9:37 pm
why u have just three choices ? is the answer 1 and 2 that means >0 and >5

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by vipulgoyal » Wed Feb 27, 2013 10:33 pm
its a serial no not less then or greater then

the sum of the 10 numbers is 28, if the range of these numbers is 2, how many 3 are there

1 0
2 5
3 9

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by Anurag@Gurome » Wed Feb 27, 2013 10:52 pm
vipulgoyal wrote:the sum of the 10 numbers is 28, if the range of these numbers is 2, how many 3 are there
Let us assume the a is the smallest number and b is the largest number.
Hence, b = (a + 2)

Now let us consider the two extreme cases,
  • When all the intermediate numbers are equal to the smallest
    sum = (9a + b) = (10a + 2) --> a = (28 - 2)/10 = 2.6 --> b = 4.6
    When all the intermediate numbers are equal to the largest
    sum = (a + 9b) = (10a + 18) --> a = (28 - 18)/10 = 1 --> b = 3
Hence, we can at least have the following two sets
  • {2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 4.6} ---> No 3
    {1, 3, 3, 3, 3, 3, 3, 3, 3, 3} ---> Nine 3
Hence, we can only conclude that the minimum number of 3s in the set is 0 and the maximum number of 3s in the set is 9.

Note : In case someone is looking for some examples with 2 or 3 or etc number of 3 in the set, here you go...
{2.4, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 3, 4.4} ---> One 3
{1.7, 2.6, 2.6, 2.6, 2.6, 2.6, 2.6, 3, 3, 3.7} ---> Two 3s
{1.6, 2.6, 2.6, 2.6, 3, 3, 3, 3, 3, 3.6} ---> Five 3s
etc etc
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by sana.noor » Wed Feb 27, 2013 11:11 pm
is this a gmat question?
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by Anurag@Gurome » Wed Feb 27, 2013 11:42 pm
sana.noor wrote:is this a gmat question?
Conceptually yes, but not in the format it has been posted.
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by aditya8062 » Thu Feb 28, 2013 4:21 am
to the original poster : kindly put the question using a nice qwerty keyboard and plz put the answer as well

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by vipulgoyal » Thu Feb 28, 2013 4:23 am
the answer is all,very well explained thanks Anurag