The citizens of planet Oz are 4 fingured and thus have developed a number system in base 4. A certain street i n Oz contains 100 buildings bumberred from 1 to 100. How many 2's are used in numbering these buildings? Express your answer in base 10.

• ANS:8
  EXP:
  no of any digit used from 1 to 100=2*B
  thus no of 2=2*4
  =8
• 13 years agoHelpfull: Yes(23) No(5)
• ans is 8.
  in the question they have mentioned it as "base 4", so we should take numbers from from 0 to 4, so take the number series as:
  0,1,2,3,4,
  11,12,13,14,
  21,22,23,24,
  31,32,33,34,
  41,42,43,44, hence in abv series ter are 8 2s.
  (since the base is 4 consider the number series only till 40's.
  if base 8 then consider till 80's and so on........)
  or the question can also be solved by using formula.... 2*n ==> 2*4=8.
• 13 years agoHelpfull: Yes(8) No(6)
• 2
  houses r numbered 1-100..
  first2 will come frm 0-9
  2nd 2 in 12
  then 10 2in twenty series
  3 rd in 32
  likewise when we count all 2 ans is 20
  evrything else is to confuse u
• 13 years agoHelpfull: Yes(5) No(8)
• number of 2'S between 1 to 10 =1
  number of 2'S between 11 to 20=2
  number of 2'S between 21 to 30=4
  number of 2'S between 31 to 100=1
  number of 2's=8
• 13 years agoHelpfull: Yes(3) No(5)
• basically no. of 2's from 1 to 100 are 2,12,20,21,22,23,24,25,26,27,28,29,32,42,52,62,72,82,92 i.e 20.
  by converting this 20 into base(10) whatever he will give, that will be the answer.
• 13 years agoHelpfull: Yes(2) No(2)
• ans is 9... 2,12,21,22,23,24,32,42...22 is having two twos...
• 13 years agoHelpfull: Yes(2) No(4)
• in this type of question apply this rule...
  no.of any digit within 0-100=20;
  so no. of 2's=20
  number system is in base 4
  so=2*(4^0)+ 0*(4^0)=8
• 13 years agoHelpfull: Yes(2) No(5)
• 20 because 2 occur 20 times in 100
• 13 years agoHelpfull: Yes(1) No(5)
• the 2s are.....2,12,20,21,22,23,32 so number of 2 in decimal=8
• 13 years agoHelpfull: Yes(1) No(1)
• Ans. 8
  
  (4^2- 3^2) numbers contain 2. there is 22 also. total 2s= 6+2=8
• 13 years agoHelpfull: Yes(0) No(7)