100 students appeared in 2 tests.60 students passed 1st test. 40 students
passed in the 2nd test. 20 students passed in both 1 and 2 tests. what is the
probability of the students who failed in both tests?

• no. of pass student in at least one subject =60+40-20=80
  
  hence student failed in both subject =100-80=20
  
  probability 20/100=1/5
  
• 8 years agoHelpfull: Yes(2) No(1)
• no. of pass student in at least one subject =60+40-20=80
  hence student failed in both subject =100-80=20
  probability 20/100=1/5
• 8 years agoHelpfull: Yes(1) No(1)
• prob of pass the exam=5/6
  hence prob of failed=1/6
• 8 years agoHelpfull: Yes(0) No(0)
• total pass student=80
  no of fail student=100-80=20
  prob of fail student=20/100=1/5
• 8 years agoHelpfull: Yes(0) No(0)