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 3s are used in numbering these buildings?Express your answer in base 10
a) 54 b) 64 c) 265 d) 192

• ans is d)192
  bcz there are 300 no of 3s in between 1 and 1000 (eg. 20 3s between 1 and 99 and 20 3sben 199 and so on. bt there are 120 3s between 300 and 399. so total no of 3s are 20+20+120+20+20+20+20+20+20+20=300). 300=3*8^2=3*64=192 in base 10 system.
• 13 years agoHelpfull: Yes(36) No(6)
• 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 :)
• 13 years agoHelpfull: Yes(24) No(6)
• In 8 base there can't be numbers more than 7. So 3s will be like 3,13,23,30,31,32,33,34,35,36,37,43,53,63,73 so that's make 16.So upto 1000 there will be 8x16=128 3s and from 300 to 377 there is 64 3s (counting all 3s ). so that's make the answer 192.
• 13 years agoHelpfull: Yes(18) No(2)
• Ans: 192
  
  Number 3 in 1-100 comes 20 times.
  101-200-> 20 times
  201-300-> 20 times
  301-400->120 times
  401-500-> 20 times
  501-600-> 20 times
  601-700-> 20 times
  701-800-> 20 times
  801-900-> 20 times
  901-1000-> 20 times
  Total times: 300 times (any no. from 1 to 9 except 0 will occur 300 times)
  8 based planet.. then
  3*8^2 + 0*8^1 + 0*8^0 = 192
• 11 years agoHelpfull: Yes(15) No(0)
• There are 1000 in base 8 buildings ie,512 buildings accg to dec no system.Now the houses are no:red in base 8.ie,for 512 housesnumbering will be 1-7,10-17,17-27,.........,70-77(from 1-100)similarly name 512 houses using base 8 ie, from 100-177,200-277,..........700-777,1000.
  total no of 3 from (0-77.....200-277) is 16,300-377 is 16+64,rest also is 16.
  so total no of 3 will be 16*8+64=192.
• 13 years agoHelpfull: Yes(9) No(5)
• (512*3)/8=192
• 13 years agoHelpfull: Yes(8) No(3)
• in 1 to 1000 there are 300 3s used.. in between evry 100.. there are 20 no 3s,, counting 2 3s in 33.. so 20*10=200 and as is 300-399 there are 100 3's at d begining. so total 3=300.
  in base 10.. no(3)=3*6^2+0+0=108 :)
• 13 years agoHelpfull: Yes(5) No(9)
• 192
• 13 years agoHelpfull: Yes(5) No(8)
• 192 is the answer.
• 13 years agoHelpfull: Yes(2) No(8)
• 192
• 13 years agoHelpfull: Yes(1) No(3)
• no of 3's=300
  in base 8=3*8*8=192
• 8 years agoHelpfull: Yes(0) No(0)