Question

The XYZ company hiring candidates for office assistant posts, The question paper consists of 150
questions where every question carries one mark and consists of 4 options. Each incorrect answer
fetches 0.25 marks to the candidate. Suppose 1000 candidates select all their answers randomly with
uniform probability. The expected marks total obtained by all these candidates is.​

Answer 1

Answer:

Answer is option D.

Probability of choosing the correct option =

1

4

Probability of choosing a wrong option =

3

4

So, expected mark for a question for a student =

1

4

×1+

3

4

×(−0.25)=0.0625

Expected mark for a student for 150 questions = 0.0625×150=9.375

So, sum total of the expected marks obtained by all 1000 students = 9.375×1000=9375.