How many four-digit numbers that do not contain the digits 3 or 6 are there?


a) 2401
b) 3584
c) 4096
d) 5040
e) 7200

• 7*8*8*8=3584(b)
  first place 0 3 6 not allowed so available digits 10-3=7
  same 4 remaining
  
• 11 years agoHelpfull: Yes(30) No(5)
• b) 3584
  Frm 0 to 9 ,after removing 3 & 6 ,we get 8 numbers.
  Now , 0 will nt be placed at 1000th place ,
  So the ans is =8*8*8*7=3584
• 11 years agoHelpfull: Yes(8) No(4)
• ans is 3584
  7*8*8*8= 3584
  bcoz in first place we cant write 0,3,and 6
  and all other palces we can't write 3 and 6
  so 7*8*8*8= 3584
• 11 years agoHelpfull: Yes(7) No(0)
• u have to assume repition is allowed
  now in 4 digit nu u can use from 1 to 9 except 6 and 3 so ways =7
  in thousands place 8 ways since zero can be used
  in hundreds 8 ways
  in unit 8 ways
  7*8*8*8=3584
• 11 years agoHelpfull: Yes(3) No(0)
• 7*8*8*8=3584
• 11 years agoHelpfull: Yes(2) No(1)
• 7*8*8*8=3594
• 11 years agoHelpfull: Yes(2) No(1)
• 7*8*8*8=3584
• 11 years agoHelpfull: Yes(2) No(1)
• 7*8*8*8=3584
• 11 years agoHelpfull: Yes(1) No(0)
• ans is =8*8*8*7=3584
• 11 years agoHelpfull: Yes(1) No(1)
• 3584
  on thousandth place - possibility of 9,8,7,5,4,2,1
  on hundredth place - 9,8,7,5,4,2,1,0
  similarly on tenth place n units place - 9,8,7,5,4,2,1,0
  so .... 7*8*8*8 = 3584
• 9 years agoHelpfull: Yes(1) No(0)
• ans is b
  
  it is similar to making a 4 digit num without using 3 and 6 when repitition is allowed which is nothing but 7*8*8*8
• 11 years agoHelpfull: Yes(0) No(0)
• 488->1000
  x ->7000
  x=3416
  7000-3416
  answer is b) 3584
• 11 years agoHelpfull: Yes(0) No(0)
• 7*8*8*8=3584(b)
  
  
• 9 years agoHelpfull: Yes(0) No(0)