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![[Post New]](/templates/default/images/icon_minipost_new.gif) 19 Dec 2007 19:12:31 IST
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A 5 digit no divisible 3 is to be formed using the digits 0,1,3,4,5 without repetition. the total no of ways in which this can be done is Ans-216. Please solve this question with good explaination.
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19 Dec 2007 19:17:14 IST
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check ur ques, for divisibility sum of digits to be a multiple of three, but 5+4+3+1+0 not divisible by 3.
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19 Dec 2007 19:39:00 IST
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Sorry the digits are 0,1,2,3,4,5.Now solve it.
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19 Dec 2007 20:59:25 IST
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take 5 nos at a time and see divisibility by 3.
only two cases.
0,1,2,4,5 =>4*4*3*2*1 [since zero cannot be in first place]
1,2,3,4,5 =>5*4*3*2*1
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Select five numbers such that their sum is a multiple of 3.
Two possible cases : (1,2,3,4,5) ; (01,2,4,5)
no. of 5-digit numbers that can be formed using (1,2,3,4,5) = 5! = 120
no. of 5-digit numbers that can be formed using (0,1,2,4,5) = 4x4x3x2x1 = 96 (since 1st place cant be 0).
so total numbers = 120+96 = 216
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Bipin Kumar Dubey
Chemical Dept.
IIT Kharagpur
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this reply: 10 points
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