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Integers

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Integers

by vinayreguri » Sun Jun 12, 2011 7:15 am
How many number of integers between 300 & 500, exclusive, are divisible by 9

OA: 22
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by vinayreguri » Sun Jun 12, 2011 7:17 am
My approach : 500-300/9=22.2

OR

300/9=33.3333 round off to 34 i.e 34*9=306
500/9=55.5555 round off to 55 i.e 55*9=495
total 55-34+1=22
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by Anurag@Gurome » Sun Jun 12, 2011 7:29 am
vinayreguri wrote:How many number of integers between 300 & 500, exclusive, are divisible by 9
Yes your approach is correct.
Another approach is:
  • First integer divisible by in the given range = 306
    Last integer divisible by in the given range = 495

    Hence, number of integers divisible by 9 in the given range = (495 - 306)/9 + 1 = (21+ 1) = 22
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by Vish_ » Mon Jun 13, 2011 3:17 am
The method I used to get to the answer was:

If from 0 to 100 there are 11 integers divisible by 9.
Thus from x00 to y00 there must be 11*(y-x) integers.
In this case x = 3 and y = 5
Hence 11* (5 - 3) = 22

Is this the right way to go about it?

Thanks,
Vish
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