In T.Nagar the building were numbered from 1 to 100.Then how many 4's will be present in the numbers?
a)18 b)19 c)20 d)21

• just count the number of 4's from 1 to 100
  (4,14,24,34,40,41,42,43,44,45,46,47,48,49,54,64,74,84,94)
  totally there are 20 (two 4's in 44)
• 14 years agoHelpfull: Yes(44) No(4)
• Number of 4's from 1 to 39 = 4(i.e., 4,14,24,34)
  Number of 4's from 40 to 49 = 11(i.e., 40,41,42,43,44,45,46,47,48,49)
  Number of 4's from 50 to 100 = 5(i,e., 54,64,74,84,94)
  Total number of 4's = 4+11+5 = 2
  Hence, option is 'c'
• 14 years agoHelpfull: Yes(19) No(4)
• n*b^(n-1)
  where n power..100=10^2 so n=2
  b=bace=10
  2*10^(2-1)=20
  
• 14 years agoHelpfull: Yes(13) No(3)
• Number of 4's from 1 to 39 = 4(i.e., 4,14,24,34)
  Number of 4's from 40 to 49 = 11(i.e., 40,41,42,43,44,45,46,47,48,49)
  Number of 4's from 50 to 100 = 5(i,e., 54,64,74,84,94)
  Total number of 4's = 4+11+5 = 20
  Hence, option is 'c'
• 14 years agoHelpfull: Yes(7) No(1)
• sol:4
  
• 14 years agoHelpfull: Yes(2) No(13)
• 4,14,24,34,40,41,42,43,44,45,46,47,48,49,54,64,74,84,94
  Don't forgot to count 44 i.e 2 4's will be there.
  so total is 20.
• 10 years agoHelpfull: Yes(0) No(0)
• ans is 20 is currect
• 9 years agoHelpfull: Yes(0) No(0)