(Q). In an examination a student has to write 8 papers & has to pass in each paper to pass the exam. In how many ways a student can fail in the exam?
Solution:-
For every paper there are 2 ways of selection → Pass or Fail.
So total number of ways is 2⁸ = 256 & out of these ways one way is also counted when student pass in every paper i.e. student pass the exam in 1 way.
So total number of ways that the student can fail is = 256 – 1
= 255 Answer