How many six digits number can be formed using the digits 0 to 5, without repetition such that the number is divisible by the digit at its unit place.
Option
a. 420
b. 426
c. 432
d. none

• b. 426
  
  0 can't hold 1st or last position
  -----0 => not possible(a no. can't be divided by 0)
  -----1 => 4*4*3*2= 96 (divisible by 1)
  -----2 => 4*4*3*2= 96 (divisible by 2)
  -----3 => 4*4*3*2= 96 (divisible by 3 as 0+1+2+3+4+5=15)
  
  for a no. to be divisible by 4, last two digit should be 04,24
  ----04 => 4*3*2 = 24
  ----24 => 3*3*2 = 18
  
  -----5 => 4*4*3*2 = 96 (divisible by 5)
  
  total no. formed = 96*4 + 24 + 18 = 426
  
• 10 years agoHelpfull: Yes(83) No(5)
• Start 1 by 1..
  1st consider the case for 0 then we have 0 cases for that as no number can be divisible by 0 so =0
  
  now for 1 , lets fix 1 at unit place then we left with 4 choices at 1st place from left as 0 again cant be on 1st position so number of cases
  - 4! * 4 = 96
  
  for 2, same as 1 ie :: 96
  for 3 :: 96
  but for 4 only digit ----04 and ----24 can be divisible by 4 so we have...
  4! + 3!*3= 42
  for 5 ::96
  adding :: 96+96+96+42+96 = 426
  
  426 is solution
• 10 years agoHelpfull: Yes(5) No(0)
• 426 is right ....
• 10 years agoHelpfull: Yes(3) No(0)
• 600 numbers
• 10 years agoHelpfull: Yes(1) No(5)
• Rakesh
  Coming to divisible by 4
  We have 04 12 20 24 40
  Why u have taken only 04 24
• 10 years agoHelpfull: Yes(1) No(1)
• 426 is ryte ans
• 10 years agoHelpfull: Yes(1) No(0)
• one more thing rakesh u r rit bt when divisible by 4 then last two no may be ---40 now for this
  ---40=>3*2*1=6
  so total 326+6=332
• 10 years agoHelpfull: Yes(1) No(1)
• sorry 426+6=432
• 10 years agoHelpfull: Yes(1) No(1)
• i m getting 420 ... m i right.
• 10 years agoHelpfull: Yes(0) No(8)
• 6!-3*4!
  none
• 10 years agoHelpfull: Yes(0) No(1)
• Rakesh
  am unable to get it , can u plz make it simlpe
• 10 years agoHelpfull: Yes(0) No(0)
• point missed on divisiblity by 4 ,there should be 12
• 10 years agoHelpfull: Yes(0) No(2)
• Where it is mentioned it should be divisible by 4??
• 10 years agoHelpfull: Yes(0) No(0)
• @tirupathi
  
  20 and 40 are already discarded while checking for 0 at unit place
  and 12 is already considered in the case with 2 at unit place
• 10 years agoHelpfull: Yes(0) No(0)
• they ask 6 digit numbers not 5 digit numbers right????
  
• 10 years agoHelpfull: Yes(0) No(0)