there is a 3X5 matrix of points .. find the probability of forming a triangle .
matrix is as shown
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• 434/455 I wrote. Although I found the denominator right, I have doubts in Numerator. For denominator 15c3/3factorial which gives 455. I tried to count straight lines which can be formed by choosing 3 dots. But they were more than 21 so I wrote the least possible option which was 434/455
• 9 years agoHelpfull: Yes(7) No(3)
• was that a dummy question?
  see 5 points in each row.. we can select three points in 5c3 ways
  for three rows 3*5c3 ways
  for each column 5 ways
  for each diagonal 6 ways
  adding all these we get (30+5+6) ways .. these are ways of selecting points which are collinear
  subtracting it from 455 we get 414
  hence ans should hav bn 414/455.. nd i dont think that was a option
• 9 years agoHelpfull: Yes(7) No(0)
• 449/455
  15C3 GIVES DENOMINATOR
  
• 9 years agoHelpfull: Yes(5) No(0)
• SHIKHA You forgot to minus 2 more diagonals answer will be 412/455. But there was no answer right..? What is dummy question ?
• 9 years agoHelpfull: Yes(5) No(1)
• questions are repeating.. matrix value is not given.. the matrix/ grid of points and we have to find probability of selecting three points so that they from a triangle.. .. this question came today in my tcs written
• 9 years agoHelpfull: Yes(3) No(0)
• all are chutiyass ans is 412 / 455
• 8 years agoHelpfull: Yes(3) No(0)
• dummy questions are those questions which have no correct answer.. they are meant not to be attempted.. hence leading to more negatives
• 9 years agoHelpfull: Yes(2) No(0)
• matrix value v need... m4 questions are repeating or not?
  
• 9 years agoHelpfull: Yes(1) No(0)
• it is 438/455
  
• 9 years agoHelpfull: Yes(1) No(0)
• ans is=420
• 9 years agoHelpfull: Yes(0) No(1)
• i think 438
• 9 years agoHelpfull: Yes(0) No(0)