In T. Nagar the building were numbered from 1 to 1000.Then how many 4’s will be present in the numbers? in octal

• no. of 4s between 1 & 1000 can be found from this formula,
  3*B^2 ; where B is base.
  here B=8,
  so, no. of 4s between 1 & 1000= 3*8^2=3*64=192.
  (NB- this formula is also applicable to find no of 2s,3s.....9s b/w 1 & 1000)
• 13 years agoHelpfull: Yes(18) No(0)
• 1-7: 1 four
  10-17: 1 four
  ...
  40-47 : 9 four
  ....
  70-77: 1 four
  total: 7+9 = 16 four
  fours in 1-777 (excluding 4's at ten's place)=16*8=128
  
  400 - 407 = 8 fours(excluding 4's at once place)
  ...
  470-477 = 8 fours(excluding 4's at once place)
  total 4's in 400 series (excluding 4's at once place) - 8*8=64
  
  total 4's in 1 -777 = 128+64=192
  
• 13 years agoHelpfull: Yes(3) No(0)
• the answer is 192.
• 13 years agoHelpfull: Yes(2) No(0)
• in first 1oo no.'s 20 4's are present..
  likewise in 1000 no.'s 201 are present..
• 13 years agoHelpfull: Yes(0) No(10)
• for these type of question we have first to define the values till 80 because octal,hence we have 4,14,24,34,44,54,64,74....hence cal till ones ,tens and units place of each....8*8+8*8+8*8=192
• 13 years agoHelpfull: Yes(0) No(2)