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Question Number 111831 by Aina Samuel Temidayo last updated on 05/Sep/20

Let N be the greatest multiple of 36 all  of whose digits are even and no two of  whose digits are the same. Find the  remainder when N is divided by 1000.

LetNbethegreatestmultipleof36allofwhosedigitsareevenandnotwoofwhosedigitsarethesame.FindtheremainderwhenNisdividedby1000.

Answered by Rasheed.Sindhi last updated on 05/Sep/20

36=4×9  ^▶ A number is divisible by 36 if it      is divisible by 4 & 9  ^▶ A number is divisible by 9 if     sum of digits of the number is      divisible by 9.  ^▶ A number is divisible by 4 if     the two digit number composed     of one′s & tens is multiple of 4       N consists of distinct & even       digits :0,2,4,6,8      Only possible combination of digits for     which the formed number may be      divisible by 9 is 0,4,6,8.(sum       will be 0+4+6+8=18 which is      divisible by 9.     N is greatest so most significant     digit must be 8 and next be 6 if      possible.      8 6 _ _.      The remaining digits are 0 & 4     Two 2-digit numbers are possible     04 & 40.Both numbers are     fortunately divisible by 4.But    for N(the greatest) 40 is only    option.   ^• So now the number is 8640.   ^• The remainder on dividing by       1000 is obviously :                     640

36=4×9Anumberisdivisibleby36ifitisdivisibleby4&9Anumberisdivisibleby9ifsumofdigitsofthenumberisdivisibleby9.Anumberisdivisibleby4ifthetwodigitnumbercomposedofones&tensismultipleof4Nconsistsofdistinct&evendigits:0,2,4,6,8Onlypossiblecombinationofdigitsforwhichtheformednumbermaybedivisibleby9is0,4,6,8.(sumwillbe0+4+6+8=18whichisdivisibleby9.Nisgreatestsomostsignificantdigitmustbe8andnextbe6ifpossible.86__.Theremainingdigitsare0&4Two2digitnumbersarepossible04&40.Bothnumbersarefortunatelydivisibleby4.ButforN(thegreatest)40isonlyoption.Sonowthenumberis8640.Theremainderondividingby1000isobviously:640

Commented by Aina Samuel Temidayo last updated on 05/Sep/20

Cool. Thanks.

Cool.Thanks.

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