How many positive integers less than 500 can be formed using the numbers 1,2,3,and 5 for digits, each digit being used only once.

• 3 digits no formed= 3*3*2 (5 cant come at place,no should be less than 500)
  =18
  2 digit no formed=4*3
  =12
  1 digit no formed=4
  total positive integers=18+12+4
  =34
• 10 years agoHelpfull: Yes(90) No(15)
• 34
  exp:
  one digit nos=4
  two digit nos=4c2
  three digit nos which starts with 1 is 6
  three digit nos which starts with 2 is 6
  three digit nos which starts with 3 is 6
  so total 4+12+18
• 10 years agoHelpfull: Yes(15) No(10)
• let us consider _ _ _(3 digit num).
  as it is given that the nums should be less than 500 so we shouls not use 5 in 100's place
  out of 3 (1,2,3) 100's place can be filled by one num in 3c1 ways=3
  out of 3 remaining 10's place can be filled by one num in 3c1 ways=3
  out of 2 remaining 1's place can be filled in 2c1 ways=2
  therefore no of ways=3*3*2=18ways
• 10 years agoHelpfull: Yes(13) No(10)
• @priyanka:4c2=6 know?
• 10 years agoHelpfull: Yes(7) No(7)
• FOR SINGLE DIGIT NO.=4 WAYS
  FOR DOUBLE DIGIT NO.= 4! WAYS
  FOR THREE DIGIT NO. 3! WAYS
  4+4!+3!=34
• 7 years agoHelpfull: Yes(6) No(0)
• when 5 is placed at 100th position,total combination=3!
  without any restriction=3!
  so,less than 500=4!-3!=18 ways.
• 10 years agoHelpfull: Yes(4) No(11)
• Ans=34
  Single digit numbers = 4
  Double digit numbers = 4 x 3 = 12
  Three digit numbers = 3 x 3 x 2 x 1 = 18
  Total = 4+12+18=34
• 9 years agoHelpfull: Yes(4) No(7)
• 34
  
  one digit nos=4
  two digit nos=4c1*3c1=12
  three digit nos which starts with 1 is 6
  three digit nos which starts with 2 is 6
  three digit nos which starts with 3 is 6
  so total 4+12+18
  
• 8 years agoHelpfull: Yes(3) No(0)
• 1 digit numbers= (4!)/(3!)= 4;
  2 digit numbers= (4!)/(2!)= 12;
  3 digit numbers= (4!)/(1!)= 24; but 512, 513, 521, 523, 531, 532 these 6 numbers are greater than 500, so 24-6= 18;
  So that answer is 18+12+4= 34.
• 7 years agoHelpfull: Yes(3) No(0)
• 3 digits number can be formed by
  3*3*2 ways since 5 cannot be the first digit
  so 18
  No two digit or three digit number can be formed because there is no 0 in the digit list
  
• 9 years agoHelpfull: Yes(2) No(4)
• Single digit number = 4
  Double digit number = 4××3 = 12
  Three digit numbers = 3××3××2= 18 (∵∵ If Hundred's place is 5, then the number is greater than 500)
  Total = 34.
  
• 7 years agoHelpfull: Yes(1) No(0)
• Possible ways
  1 digit => 4
  2 digit=>4*3=12
  3 digit=>3*3*2=18
  total=4+12+18=34
  
• 7 years agoHelpfull: Yes(1) No(1)
• possible numbers are ly 18 try to put all numbers like 123 125 ,...upto.352
• 9 years agoHelpfull: Yes(0) No(3)
• 4+12+24=40
• 4 years agoHelpfull: Yes(0) No(0)