permutation

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permutation

by romitvsingh » Mon Oct 31, 2011 8:24 pm
How many 5 digit numbers can be formed which are divisible by 3 using the numerals 0, 1, 2, 3, 4, 5 (WITHOUT REPETITION)

Possible AnswersSelected Possible Answer
A. 216

B. 3152

C. 240

D. 600

E. 305
Source: — Problem Solving |

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by rijul007 » Mon Oct 31, 2011 8:45 pm
divisibility rule of 3 => sum of all digits is a multiple of 3

no of selections of 5 nos such that sum is a multiple of 3=> 2
{1,2,3,4,5}
{0,1,2,4,5}


Total no of arraongements => 5! + 4*4! => 120 + 96 => 216