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Re: [2IIM CAT Prep]

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  • RAHAMATHULLAH ELYAS
    ..the ans is 8.. error in 1st line in previous mail ... -- regards, rahmath
    Message 1 of 1 , Aug 2, 2011
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      ..the ans is 8.. error in 1st line in previous mail

      On Tue, Aug 2, 2011 at 7:41 PM, RAHAMATHULLAH ELYAS <raham90@...> wrote:
      ..the ans is not  2.. its '4'
      ..the way u ppl proceeded is right, but u forgot dat between 21 - 30 der are two 5's ..i.e. 25=5*5 ..
      one of the 5 multiplied wid 2 nd other wid 4..which gives two zeros..
      der fore it will be 8*8*2..whose unit place will be 8


      On Fri, Jul 22, 2011 at 1:05 PM, pradeep barola <mjain.pkb@...> wrote:
       

      I am also getting 2 as answer:

      1*2*3*4*5*6*7*8*9= it has 8 as the last non zero digit

      and doing this three times 8*8*8 has 2 as last non-zero digit

      Pradeep


      On Tue, Jun 21, 2011 at 3:32 PM, deepak narayanan <deepakraam@...> wrote:
       


      Q1. There are 7 zeroes in the end of 30! (factorial 30). Which digit precedes these zeroes?
       
      a.8
      b.3
      c.4
      d.7


      I could get the number as 2 .

      Taking the first 10 numbers (10!) will end in 

      10! = 1*2*3*4*5*6*7*8*9*10 

      Eliminating: 1, 2,5 as they contribute only to the zeros we get 

      3*4*6*7*8*9 = 8. 10! = 32...800.So,8 precedes the zeroes.

      Working on the same fashion for 30!,I'm getting 2 as the number that is not listed in the options.

      Anything wrong?

      -Deepak.




      --

      Pradeep






      --
      regards,
       rahmath

      ' 




      --
      regards,
       rahmath

      ' 

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