Multiple choice

Students in a class of strength 'p' have roll numbers 1, 2, 3, 4… p - 1, p. Take a student with roll number 'n'. What is the probability that either he or someone with a roll number higher than him is selected at random?

  1. 1/p

  2. (p - n)/p

  3. (p - n + 1)/p

  4. 1/n

  5. n/p
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There are (p-n) students in the class with roll number greater than 'n'. Add one to this to include the student with roll number 'n'. Hence this gives the probability that the selected student has his roll number 'n' or greater than 'n'. This is the required probability.

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