How many 4-digit numbers contain no.2?

• i thought it be easier to understand and to solve the problem by this way
  total number of four digit numbers =9000 (i.e 1000 to 9999 )
  we calc the number not having no 2 in it....
  now consider the
  units place it can be selected in 9 ways (i.e 0,1,3,4,5,6,7,8,9)
  tens place it can be selected in 9 ways (i.e 0,1,3,4,5,6,7,8,9)
  hundreds place it can be selected in 9 ways (i.e 0,1,3,4,5,6,7,8,9)
  thousands place can be selected in 8 ways (i.e 1,3,4,5,6,7,8,9) here '0' can not be taken
  total number of numbers not having digit 2 in it =9*9*9*8 =5832
  total number of numbers having digit 2 in it = 9000-5832
  =3168
• 11 years agoHelpfull: Yes(87) No(4)
• 10*10*10*9-9*9*9*8=3168
• 11 years agoHelpfull: Yes(8) No(1)
• total of 4 digit no=9000
  total of 4 digits donot contain 2=5832
  ans 9000-5832=3168
• 11 years agoHelpfull: Yes(7) No(5)
• desired result=total no of 4 digit no - total no of 4 digit no not containing 2
  result=9*10*10*10-8*9*9*9=3168
• 11 years agoHelpfull: Yes(6) No(2)
• no of 2 betwn
  2000 to 2999= 1000(for 1000 place)
  for 100 place = 900
  for 10 place = 900
  for 1 place = 900
  so 1000+900+900+900 = 3700 2's present
• 11 years agoHelpfull: Yes(6) No(4)
• the answer is 3168
• 11 years agoHelpfull: Yes(0) No(2)
• unit digit=2
  ten digit=2 hundred digit=2 thousand digit=2
  2+2*10+2*100+2*1000=2+20+200+2000=6000
  
• 10 years agoHelpfull: Yes(0) No(1)
• 1000+800=1800
• 9 years agoHelpfull: Yes(0) No(0)
• 4 digit no contains 2 = total 4 digits no - 4 digits does not contain
  9*10*10*10 - 8*9*9*9
  3168
• 9 years agoHelpfull: Yes(0) No(0)
• The easiest way to do this:
  Find the total number of 4 digit numbers. This is easy (from 1000 - 9999): 9000 numbers in all.
  Find out how many of them do not contain the number 2.
  There are 9 digits with the exception of 2. The second, third and fourth digit (from right to the left) make 9 x 9 x 9 = 729 possibilities.
  There cannot be a 0 wither at the thousand's place so there are 8 possibilities.
  Therefore, there are 8 x 729 = 5832 four-digit numbers that do not contain 2.
  Thus, there are 9000 - 5832 = 3168 four-digit numbers that do contain the digit 2.
• 6 years agoHelpfull: Yes(0) No(0)