How many 4 digit number are there made by 2?

• total 4 digit number 9000
  digits that do not include 2 can found by permutation
  as on units place 9 ways to fill
  same on tenth and hundredth place there are 9 ways to fill
  but on thousandth place only 8 ways to fill
  therefore
  no. not including 2 would be=8*9*9*9=5832
  no. including 2 will be=9000-5832
  that is 3168
  
• 10 years agoHelpfull: Yes(19) No(0)
• Ans is 3700
• 10 years agoHelpfull: Yes(2) No(6)
• 3697 coz in 3700 , 3333 is counted four times so we need to substract 3 hence ans wil be 3700
• 10 years agoHelpfull: Yes(1) No(1)
• no. of ways when unit digit is 2 = 9 x 10 x 10 = 900
  no. of ways when tens digit is 2 = 9 x 10 x 10 = 900
  no. of ways when hundreds digit is 2 = 9x 10x 9 = 900
  no. of ways when thousands place digit is 2 = 10x10x10 = 1000
  total = 900+900+900+1000
  3700
• 10 years agoHelpfull: Yes(1) No(1)
• sry hence it will b 3697
• 10 years agoHelpfull: Yes(0) No(0)
• 1. With number 2
  2222 one possibility
  2. With two numbers
  4!/2!2! = 6 possibilities
• 10 years agoHelpfull: Yes(0) No(0)
• Ans will be 3168
• 10 years agoHelpfull: Yes(0) No(0)
• 9*10*10*10-8*9*9*9=3168
• 10 years agoHelpfull: Yes(0) No(0)