In T nagar there are residential & commercial buildings. For residential buildings they number as 1 to 100. For commercial buildings, corporation numbered them with prime numbers between 150 and 200. How many times 6 will appear in building numbers?

• 1 to 100 n0. of 6 is
  6,16,26,36,46,56,60,61,62,63,64,65,66,67,68,69,76,86,96( 20 numbers)
  from 150 to 200, prime numbers are
  163,167(2 n0.s)
  so tatal times 6 will appear=22
  
• 11 years agoHelpfull: Yes(37) No(7)
• In between 1 to 100.
  6,16,26,,,,60,61,,,66,,69,,76,,,96,,=====20
  and In between 150 to 200 prime numbers
  151,157,163,167,173,179,181,191,193,197,199=====only in number 6 is present.
  so total=20+2=22
• 11 years agoHelpfull: Yes(13) No(2)
• 21 is the answer ..... 6 appears 19 times between 1 to 100.and 2 times between 150 to 200 .so total answer is 21
  
• 11 years agoHelpfull: Yes(6) No(15)
• from 6 to 96 no of 6= 20
  and from 150 to 200, prime no are only 2 having 6... i.e
  163 n 167
  total no of 6= 20+2=22 ans
• 11 years agoHelpfull: Yes(3) No(1)
• 22 since in 66 6 appear two times
• 11 years agoHelpfull: Yes(2) No(0)
• is 169 prime?
  169=13*13
• 11 years agoHelpfull: Yes(2) No(1)
• no of 6 b/w 1-100:6,16,26,36,46,56,60,61,62,63,64,65,66,67,68,69,76,86,96(19)
  and b/w 150-200:163,167,169(3)
  =19+3
  
• 11 years agoHelpfull: Yes(2) No(5)
• sorry the answer is 22(19+3)
  a correction to the first part and to the answer itself
  no of '6' in commercial buildings will be 11+8=19( i missed 61,62,63,64,65,67,68,69 in my previous solution)
  
  therefore the answer will be 19+3=22
  (second part is ok)
• 11 years agoHelpfull: Yes(1) No(0)
• between 1 to 100 there are total 20 nos of 6 - 06,16,26,36,46,56,60,61,62,63,64,65,66,67,68,69,76,86,96.
  
  between 150 to 200 the no. of prime numbers having 6 as it's digit are -
  163 & 167
  so the total times 6 will appear in the building names= 20+2 =22
• 11 years agoHelpfull: Yes(1) No(0)
• ans=22
  it will=22?
• 11 years agoHelpfull: Yes(1) No(0)
• 20
  no prime no between 150 and 200 end with 6
• 11 years agoHelpfull: Yes(0) No(2)
• 1 is fixed for thousand place..
  if we fix 6 at unit place
  then from 0,1,2...to 9 any digit can come
  so,no of ways is 1 *10 *1=10
  if we fix 6 at hundred place then
  no of ways = 1 *1*10=10
  so ,10+10=20 is ans
  
  
  
• 11 years agoHelpfull: Yes(0) No(3)
• the answer is 14 times
  
  for residential buildings: the no '6' is present in 11 numbers, i.e, 6,16,26,36,46,56,60,66,76,86,96
  
  for commercial buildings the possible categories of nos containing '6' are:
  a) nos containing '6' in the units place i.e, 156,166,176,186,196 (all these nos are ruled out as none of them is a prime no)
  b) nos containing '6' in the tenths place , i.e, 160 to 169
  out of which the prime numbers are: 163,167 and 169 only(3 numbers)
  
  therefore the total number of times '6' appears is 11+3=14 timesanswer.
• 11 years agoHelpfull: Yes(0) No(5)
• from 1 to 100 there are only 19,6's so the ans is 21.but how do you get 20,6's b/w 1 to 100
• 11 years agoHelpfull: Yes(0) No(0)
• 1 to 100 n0. of 6 is
  6,16,26,36,46,56,60,61,62,63,64,65,66,67,68,69,76,86,96( 20 numbers)
  from 150 to 200, prime numbers are 167(1 no.6)
  so tatal times 6 will appear=21
• 11 years agoHelpfull: Yes(0) No(0)
• no between 1 to 100 in which 6 apears are:
  6,16,26,....96(10 no's)+60 to 69(10 no's)= 20 no's
  prime no between 150 to 200 is only 5= 151,157,163,167,169
  so total 25 times 6 will appear in building no's...
• 11 years agoHelpfull: Yes(0) No(1)
• between 1-100 no of 6=11 and b/w 150 to 200 there is one 6 so 12 is d ri8 ans
• 11 years agoHelpfull: Yes(0) No(0)
• 1 to 100 there is no of 6=20 (6,16,26,36,46,56,60to69,76,86,96) then prime numbrs is 163,167 so its=2 then total no of 6 isd 20+2=22
  
• 11 years agoHelpfull: Yes(0) No(0)