In how many ways can we form 6 digit number from 1,2,3,4,5,6,7 so that last and second last digit must be even.

• it is not mentioned in the question that repetition is bot allowed that's why
  the answer should be "7*7*7*7*3*3"
• 11 years agoHelpfull: Yes(22) No(2)
• 3*2*5p4=720
• 11 years agoHelpfull: Yes(21) No(2)
• last 2 digits should be even(2,4,6)=3*3
  1st 4 digits can be any(1,2,3,4,5,6)=7*7*7*7
  ans=7^4*3^2
• 11 years agoHelpfull: Yes(9) No(0)
• There are 3 even numbers : 2, 4, 6.
  So, fill the last place in 3 ways. 2nd last in 2 ways.
  
  -- -- -- -- -- -- --
  5* 4* 3* 2* 1* 2* 3
  
  ans = 720 ways
• 11 years agoHelpfull: Yes(8) No(2)
• 7*7*7*7*3*3=21609
  
• 11 years agoHelpfull: Yes(5) No(4)
• 5*4*3*2*3c2*2 = 720
• 11 years agoHelpfull: Yes(3) No(1)
• last two digits in 3*2 ways and first four digits in 5! ways since we cn only use 13 5 7 or any one even number since two of them have been used
  => 5*4*3*2* 3*2
  = 720 ways
• 11 years agoHelpfull: Yes(3) No(1)
• in this question,it is not mentioned whether repitition is allowed or not.so the correct answer will be=7*7*7*7*3*3
• 11 years agoHelpfull: Yes(3) No(0)
• 5*4*3*2*2*3=720
  
• 11 years agoHelpfull: Yes(2) No(1)
• last 2 places can be filled in 3*2 ways and remaining 4 places can be filled in 5p4.Hence the sol is 5p4*3*2=720
• 11 years agoHelpfull: Yes(1) No(1)
• 3c2*2!*7c4*4!=1680
• 11 years agoHelpfull: Yes(1) No(2)
• 7*7*7*7*3*3=21609
• 11 years agoHelpfull: Yes(1) No(2)
• Total digit are 1,2,3,4,5,6,7
  First place can be filled in 4! ways
  2nd place can be filled in 3!way
  3rd place can be filled in 2!way
  4th place can be filled in 1! ways
  Since last two places consist even no so
  5th place filled in 3! Ways
  6th places filled in 2! Ways
  So total 6 digit no formed are 4!+3!+2!+1!+3!+2!=41
• 11 years agoHelpfull: Yes(0) No(5)
• A=2/3B _(1)
  B=C _(2)
  C=1/2(A+B)_(3)
  A+B+C=3000_(4)
  from (2) & (4) we get:
  2C+C=3000
  i.e.,3C=3000
  or C=1000
  
• 11 years agoHelpfull: Yes(0) No(0)
• Ragini It should be 7*7*7*7*3*2.... as only three no in two different places it is asking....
  if i am wrong then correct me please...
• 11 years agoHelpfull: Yes(0) No(0)
• Number of even number - 3
  last 2 digit must be even so 3P2 = 6
  and remaining 4 position can be arranged in 5 numbers 5P4 = 120
  120*6 = 720
• 4 years agoHelpfull: Yes(0) No(0)