How many 4 digit number contain number 2 ?

• total 4 digit no. = 9*10*10*10 = 9000
  
  not containing 2 = 8*9*9*9 = 5832
  
  total 4 digit number contain 2 = 9000 - 5832 = 3168
• 9 years agoHelpfull: Yes(79) No(2)
• Correct ans is 3168
  Total number of 4 digit numbers from 1000-9999=(9999-1000)+1=9000
  Now consider those 4 digit numbers which are not having 2 and repetition of digits is allowed
  so these 4 digit numbers can be constructed from digits 0,1,3,4,5,6,7,8,9=total 9 digits
  now number of 4 digit numbers possible from above set of digits=8*9*9*9=5832
  8(for thousand place as 0 is not allowed here)
  9(for each hundred,tens and ones place as repetition of digits is allowed)
  now all 4 digit numbers containing 2 will be
  all 4 digit numbers - all 4 digit numbers not containing 2
  9000-5832=3168 is the correct answer!!
• 9 years agoHelpfull: Yes(16) No(2)
• 900+900+900+1000=3700
• 9 years agoHelpfull: Yes(8) No(4)
• total no =3168 contains number 2
  but 3700 ways to containing no 2
  
  
• 9 years agoHelpfull: Yes(5) No(0)
• 1000+8*10*10+8*9*10+8*9*9
• 9 years agoHelpfull: Yes(1) No(3)
• Total 1800=432+432+432+504
  
  1. Let the once place have 2
  __ __ __ 2.
  
  The possibility is 6*8*9=432
  
  2. Let the tens place have 2
  __ __ 2__.
  
  The possibility is 6*8*9=432
  
  3. Hundreds place.
  __2__ __.
  
  The possibilities are 6*8*9=432
  
  4. 2 __ __ __
  
  The possibilities are 7*8*9=504.
  
  
  
  
• 9 years agoHelpfull: Yes(1) No(2)
• qstn is ((x^2)-x-1))^x+2 and soln will be 0,-1,2,-2......... so plz 1st understnd it then give the soln..... kaha kaha se soln late ho sb yar dimag kharab ho jata hai padh kar
• 9 years agoHelpfull: Yes(1) No(0)
• 1000+90+90+100=1280
• 9 years agoHelpfull: Yes(0) No(0)
• ans 3
  by putting values of x=0,-1,2 then only satisfies the eq.
  
• 9 years agoHelpfull: Yes(0) No(0)