yr anyone solve the question first digit is same as last digit and middle one are all same abbbbbba i dint remember completely ,,maine ye pehle bhi khi pda hai but yr dhan nhi aa rha...is there is anyone who solve this question?

• a and b can take 9*8 values.. 72
  
  rest as above so 24 / 72 = 12/36
• 11 years agoHelpfull: Yes(8) No(0)
• abbbbbba divisible by 3.. aisa tha shayad..
  (2*a + 6*b )/3 ..
  a and b can take distinct values from 1 to 9 ...
  
  6b is divisible by 3 so "a" can take 3, 6, 9 as values
  
  if a=3 b can be any of the other 8
  same for a= 6
  and b= 9
  
  8+8+8= 24
• 11 years agoHelpfull: Yes(4) No(0)
• question was like: what is the probability that a 8 digit number where digits of the number is any two number from 1 to 9, is divisible by 3.
  number is of form abbbbbba.
  
  1:3/36
  2:9/36
  3:8/36
  4:12/36
• 11 years agoHelpfull: Yes(3) No(0)
• answers me 4/36 option bhi tha ..
• 11 years agoHelpfull: Yes(2) No(0)
• ankit .. I left the question.. 12/36 bhi tha kya option mein??????
• 11 years agoHelpfull: Yes(1) No(0)
• @tri,kirti,richa
  home A 9616157559
  
  Answer to question:
  what is the probability that a 8 digit number where digits of the number is any two number from 1 to 9, is divisible by 3.
  number is of form abbbbbba.
  
  i have assumed "a is not equal to b"
  
  we know 2a+6*b is divisible by 3
  (2a+6*b)%3=0 => (a+3*b)%3=0
  
  a and b can have value from only 1-9
  so, possible values of a: 1,2,3,4,5,6,7,8,9
  possible values of 3*b : 3,6,9,12,15,18,21,24,27
  
  now (a%3) gives 1,2,0,1,2,0,1,2,0
  (3*b)%3 gives 0,0,0,0,0,0,0,0,0
  
  now pair those elements of a%3 and 3*b%3 where (a%3 + 3*b%3)%3=0 but dont pair where a=b
  
  finally :
  pair 3 with all number except 3 ;number becomes 30000003,31111113,32222223..
  pair 6 with all number except 6
  pair 9 with all number except 9
  
  so a can have 3 possible values 3,6,9
  b can have 8 possible values for each a
  
  ans= 3*8/9*8=1/3
• 10 years agoHelpfull: Yes(1) No(0)
• Number is of the form abbbbbba and is divisible by 3
  
  It is of the form 2a+6b, now
  it is should be divisible by 3
  
  now for a=1, b=3 (It is not divisible by 3)
  a=2 ,b=6 (It is not divisible by 3)
  a=3,b=9 (It is divisible by 3)
  and so on....
  
  therefore, for a=(3,6,9),
  
  a+6b form is divisible by 3 and not for any other value of a.
  
  so any number between a_ _ _ _ _ _a is divisible by 3 for a= 3,6 or 9.
  
  So, Finally it comes to,
  
  3C1 * 8C1 / 72
  
  3 because we have to choose from 3 values of a
  8 because we have to choose from 8 values of b
  72 because a can take 8 values and b can take 9 values overall
• 9 years agoHelpfull: Yes(1) No(0)
• koi question comp karo yar
• 11 years agoHelpfull: Yes(0) No(0)
• option the a) 3/36 b)8/36 c)9/36 @tri do u solution??
• 11 years agoHelpfull: Yes(0) No(0)
• yaar kya .. a and b ka ratio pucha tha.. Yaad nai aa raha
• 11 years agoHelpfull: Yes(0) No(0)
• @kirti did u do that question..i get 9/36 in paper..whats your??
• 11 years agoHelpfull: Yes(0) No(0)
• @tri yr it is given in the question a>b ??some equality is given
• 11 years agoHelpfull: Yes(0) No(0)