1, 4, 2, 8, 6, 24, 22, 88, ?
. How many number plate with 1,2,3,4,5 digits can be created, if repetition of numbers is not allowed?

• a) 1*4=4......4-2=2
  2*4=8......8-2=6
  6*4=24.....24-2=22
  22*4=88.......88-2=86
  Therefore, answer is 86
  
  b) 5*4*3*2*1 = 120
  
  
• 10 years agoHelpfull: Yes(20) No(17)
• for plates with a single no : 5c1
  with 2 numbers : 5c2*2!
  with 3 numbers : 5c3*3!
  with 4 nos : 5c4* 4!
  with 5 ns : 5!
  add up all these cases
• 10 years agoHelpfull: Yes(18) No(1)
• 5 digit no.=5*4*3*2*1=120
  4 digit no.=5*4*3*2=120
  3 digit no.=5*4*3=60
  2 digt no.=5*4=20
  1 digit no.=5
  total=120+120+60+20+5=325
• 9 years agoHelpfull: Yes(10) No(1)
• 2^5-1=31
  
  5c5+5c1+5c2+5c3+5c4
• 10 years agoHelpfull: Yes(2) No(2)
• plates of one digit 1
  + plates of two digits 2!
  +plates of three digits 3!=6
  +plates of four digits 4!= 24
  +plates of five digits 5!= 120
  Total 157 plates....
• 10 years agoHelpfull: Yes(1) No(6)
• 5c1+5c2*2!+5c3*3!+5c4*4!+5! = 210
• 10 years agoHelpfull: Yes(1) No(0)
• 1*4=4......4-2=2
  2*4=8......8-2=6
  6*4=24.....24-2=22
  22*4=88.......88-2=86
  ans=86
  
  5!=120
• 9 years agoHelpfull: Yes(1) No(0)
• 1,4,2,8,6,24,22,88,?
  ans is 86
  1,1*4=4,4-2=2,2*4=8,8-2=6,6*4=24,24-2=22,22*4=88,88-2=86
• 9 years agoHelpfull: Yes(1) No(0)
• giv me d crct sltn
• 10 years agoHelpfull: Yes(0) No(1)