What is the probability of forming a triangle from a 4x4 Matrix?
A.
127/140
B.
129/140
C.
131/140
D.
123/140

• 129/140
  Explanation:
  
  total outcome=16c3
  unfavorable outcome:
  if we select
  all three point from a row = 4c3*4!/3!=16;
  all three point from a col = 4c3*4!/3!=16;
  all thee point from on diognal=2*(3c3+4c3+3c3)=12;
  so total unfavorable outcome=44;
  so the required probabilty=1-44/560=129/140;
  
• 9 years agoHelpfull: Yes(22) No(2)
• Vineet, can u explain the 4c3*4!/3!
• 9 years agoHelpfull: Yes(2) No(0)
• 16c3 is sample space = 560
  3*16 - 4 is is selecting straight line = 44 bcoz 4 line common .during selecting straight line
  560-44/ 560 = 129/140
• 9 years agoHelpfull: Yes(2) No(0)
• 16c3 is sample space = 560
  3*16 + 4 is is selecting straight line = 52
  560-52/ 560 = 127/140
• 9 years agoHelpfull: Yes(1) No(6)
• 16c3 is sample space = 560
  3*16 - 4 is is selecting straight line = 44 bcoz 4 line common .during selecting straight line
  560-44/ 560 = 127/140
• 9 years agoHelpfull: Yes(0) No(6)