Form the 8 digit number using 1,2,3,4,5 repetition is allowed and it must be divisible by 4?

• Ans should be 5^7=78125
  Reason:
  We have to form 8 digit number using 1,2,3,4,5 which should be divisible by 4.
  To check divisibility for 4 we need to focus on last 2 digits.
  Last 2 digit should be divisible by 4. There can be 5 numbers that we can form-12,24,32,52,44.
  So in _ _ _ _ _ _ (_ _) last 2 digit we can use these 5 numbers. And in first six (_ _ _ _ _ _)_ _ we can use any 5 digits & as repetition is allowed. So final answer is (5*5*5*5*5*5)*5 = 5^7 = 78125.
  Hope this will help!
• 10 years agoHelpfull: Yes(86) No(3)
• ans should be 62500
  last two digit will be 12,24,32,44 because the given digits are 1,2,3,4,5
  and if the no. is divisible by 4 then last two digit must be divisible by 4.
  _ _ _ _ _ _ _ _
  
  because no is repeated so
  5c1 * 5c1 * 5c1 * 5c1 * 5c1 * 5c1 * 4c1
  =62500
• 10 years agoHelpfull: Yes(4) No(3)
• We have to form 8 digit number using 1,2,3,4,5 which should be divisible by 4.
  To check divisibility for 4, last 2 digits must also be divisible by 4.
  There can be 5 numbers that we can form-12,24,32,44,52.
  So in _ _ _ _ _ _ (_ _) last 2 digit must contain these 5 numbers.
  And in first six (_ _ _ _ _ _)_ _ we can use any 5 digits & as repetition is allowed.
  So final answer is (5*5*5*5*5*5)*5 = 5^7 = 78125.
  Hope this will help!
• 10 years agoHelpfull: Yes(4) No(1)
• 5*5*5*5*5*5*(2*2*2*)
  125000.
  form means?? there can be many numbers
• 10 years agoHelpfull: Yes(3) No(7)
• 8 digit number using 1,2,3,4,5 divisible by 4
  last two digits must be divisible by 4 so last two places can be filled in 5 ways like 12,24,44,52,32
  remaining 6 places can be filled using all 5 digits as repetition is allowed so
  5*5*5*5*5*5*5 = 5^7
  
• 9 years agoHelpfull: Yes(3) No(0)
• last digits of the no to b divisibe by 4 should be 12 24 32 52 44
  so rest 6 digits can any of 5 digits
  total ways are (5*5*5*5*5*5)*5=78125
• 9 years agoHelpfull: Yes(3) No(0)
• last two digit should be-12,24,32,52,44
  and repetition is allowed so previous 6 places can be filled by
  5^6
  so total nos =5^6*5
• 9 years agoHelpfull: Yes(2) No(1)
• It should be 2 * (5^6) = 31250
  as only two cases are possible i.e. either 12 or 24 at the end.
• 9 years agoHelpfull: Yes(1) No(0)
• ans is 5^7=78125.
  because the last two digits should be 12,24,32,44,52. acc to divisibility rule .
  so by fixing these digits at last , no. of ways for each are=5^6.
  but total cases are 5,so total no of ways are 5^7.
• 9 years agoHelpfull: Yes(1) No(0)
• a no. divisible by 4 has last 2 digits divisible by 4 so,it may be 12 16 24 28 32 36 44 48 52 56 i.e 10 , so last 2 digits can be filled by 10 ways and rest of 6 by 5 ways each as repetition is allowed..so soln will be
  5*5*5*5*5*5*5*10
• 9 years agoHelpfull: Yes(0) No(2)
• sry my explanation was abit wrong it would be 5*5*5*5*5*5*5*5 because the nos will be 12 24 32 44 52.
• 9 years agoHelpfull: Yes(0) No(0)
• 51*5!*5!*5!*5!*5!+3=123
• 9 years agoHelpfull: Yes(0) No(2)
• 5*5*5*5*5*5*2*1==15625*2=31250
  since it should be divisible by 4, so last two digit shud be divisible by 4
  in that way it has only 2 ways of 24 or 42
• 9 years agoHelpfull: Yes(0) No(0)
• last two digit should be-12,24,32,52,44
  and repetition is allowed so previous 6 places can be filled by
  6^8
  so total nos =6^8*5
• 9 years agoHelpfull: Yes(0) No(0)