The citizens of planet nigiet are 8 fingered and have thus developed their decimal system in base 8. A certain street in nigiet contains 1000 buildings numbered 1 to 1000 in base 8. How many 4's are used in numbering these buildings? Express your answer in base10.
a) 54 b) 64 c) 265 d) 192

• in between 1-100 there are 20 no of 3's.
  as 03,13,23,30,31,32,33(here we use 2 3),34,35,36,37,38,39,43,53,63,73,83,93
  
  similarly there are 20 3s in between each hundred no.
  and there are 100 3's from 300-399.. so total n of 3's are.. 100+200=300
  
  to convert it into base 10 system we use the same method as we use to convert from binary to decimel.
  
  thus (300)base8=3*8^2+0+0=192
• 6 years agoHelpfull: Yes(3) No(0)